diff --git a/ANNOUNCE b/ANNOUNCE
index 9f19880..453342f 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -1,5 +1,5 @@
 
-Libpng 1.6.10 - March 6, 2014
+Libpng 1.6.11 - June 5, 2014
 
 This is a public release of libpng, intended for use in production codes.
 
@@ -8,80 +8,51 @@
 Source files with LF line endings (for Unix/Linux) and with a
 "configure" script
 
-   libpng-1.6.10.tar.xz (LZMA-compressed, recommended)
-   libpng-1.6.10.tar.gz
+   libpng-1.6.11.tar.xz (LZMA-compressed, recommended)
+   libpng-1.6.11.tar.gz
 
 Source files with CRLF line endings (for Windows), without the
 "configure" script
 
-   lpng1610.7z  (LZMA-compressed, recommended)
-   lpng1610.zip
+   lpng1611.7z  (LZMA-compressed, recommended)
+   lpng1611.zip
 
 Other information:
 
-   libpng-1.6.10-README.txt
-   libpng-1.6.10-LICENSE.txt
-   libpng-1.6.10-*.asc (armored detached GPG signatures)
+   libpng-1.6.11-README.txt
+   libpng-1.6.11-LICENSE.txt
+   libpng-1.6.11-*.asc (armored detached GPG signatures)
 
-Changes since the last public release (1.6.9):
-  Backported changes from libpng-1.7.0beta30 and beta31:
-  Fixed a large number of instances where PNGCBAPI was omitted from
-    function definitions.
-  Added pngimage test program for png_read_png() and png_write_png()
-    with two new test scripts.
-  Removed dependence on !PNG_READ_EXPAND_SUPPORTED for calling
-    png_set_packing() in png_read_png().
-  Fixed combination of ~alpha with shift. On read invert alpha, processing
-    occurred after shift processing, which causes the final values to be
-    outside the range that should be produced by the shift. Reversing the
-    order on read makes the two transforms work together correctly and mirrors
-    the order used on write.
-  Do not read invalid sBIT chunks. Previously libpng only checked sBIT
-    values on write, so a malicious PNG writer could therefore cause
-    the read code to return an invalid sBIT chunk, which might lead to
-    application errors or crashes.  Such chunks are now skipped (with
-    chunk_benign_error).
-  Make png_read_png() and png_write_png() prototypes in png.h depend
-    upon PNG_READ_SUPPORTED and PNG_WRITE_SUPPORTED.
-  Support builds with unsupported PNG_TRANSFORM_* values.  All of the
-    PNG_TRANSFORM_* values are always defined in png.h and, because they
-    are used for both read and write in some cases, it is not reliable
-    to #if out ones that are totally unsupported. This change adds error
-    detection in png_read_image() and png_write_image() to do a
-    png_app_error() if the app requests something that cannot be done
-    and it adds corresponding code to pngimage.c to handle such options
-    by not attempting to test them.
-  Moved redefines of png_error(), png_warning(), png_chunk_error(),
-    and png_chunk_warning() from pngpriv.h to png.h to make them visible
-    to libpng-calling applications.
-  Moved OS dependent code from arm/arm_init.c, to allow the included
-    implementation of the ARM NEON discovery function to be set at
-    build-time and provide sample implementations from the current code in the
-    contrib/arm-neon subdirectory. The __linux__ code has also been changed to
-    compile and link on Android by using /proc/cpuinfo, and the old linux code
-    is in contrib/arm-neon/linux-auxv.c.  The new code avoids POSIX and Linux
-    dependencies apart from opening /proc/cpuinfo and is C90 compliant.
-  Check for info_ptr == NULL early in png_read_end() so we don't need to
-    run all the png_handle_*() and depend on them to return if info_ptr == NULL.
-    This improves the performance of png_read_end(png_ptr, NULL) and makes
-    it more robust against future programming errors.
-  Check for __has_extension before using it in pngconf.h, to
-    support older Clang versions (Jeremy Sequoia).
-  Treat CRC error handling with png_set_crc_action(), instead of with
-    png_set_benign_errors(), which has been the case since libpng-1.6.0beta18.
-  Use a user warning handler in contrib/gregbook/readpng2.c instead of default,
-    so warnings will be put on stderr even if libpng has CONSOLE_IO disabled.
-  Added png_ptr->process_mode = PNG_READ_IDAT_MODE in png_push_read_chunk
-    after recognizing the IDAT chunk, which avoids an infinite loop while
-    reading a datastream whose first IDAT chunk is of zero-length.
-    This fixes CERT VU#684412 and CVE-2014-0333.
-  Don't recognize known sRGB profiles as sRGB if they have been hacked,
-    but don't reject them and don't issue a copyright violation warning.
-  Moved some documentation from png.h to libpng.3 and libpng-manual.txt
-  Minor editing of contrib/arm-neon/README and contrib/examples/*.c
-  Fixed typos in the manual and in scripts/pnglibconf.dfa (CFLAGS -> CPPFLAGS
-    and PNG_USR_CONFIG -> PNG_USER_CONFIG).
-  Un-deprecated png_data_freer().
+Changes since the last public release (1.6.10):
+
+  Use "if (value != 0)" instead of "if (value)" consistently.
+  Changed ZlibSrcDir from 1.2.5 to 1.2.8 in projects/vstudio.
+  Moved configuration information from the manual to the INSTALL file.
+  Removed #if/#else/#endif from inside two pow() calls in pngvalid.c because
+    they were handled improperly by Portland Group's PGI-14.1 - PGI-14.3
+    when using its "__builtin_pow()" function.
+  Silence 'unused parameter' build warnings (Cosmin Truta).
+  $(CP) is now used alongside $(RM_F).  Also, use 'copy' instead of 'cp'
+    where applicable, and applied other minor makefile changes (Cosmin).
+  Don't warn about invalid dimensions exceeding user limits (Cosmin).
+  Allow an easy replacement of the default pre-built configuration
+    header with a custom header, via the make PNGLIBCONF_H_PREBUILT
+    macro (Cosmin).
+  Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes
+    with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss).
+  Made progressive reading of interlaced images consistent with the
+    behavior of the sequential reader and consistent with the manual, by
+    moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The
+    row_callback now receives the proper pass number and unexpanded rows, when
+    png_combine_row() isn't built or used, and png_set_interlace_handling()
+    is not called.
+  Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking.
+  Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann).
+  Relocated closing bracket of the sRGB profile test loop to avoid getting
+    "Not recognizing known sRGB profile that has been edited" warning for
+    ICC V2 profiles that lack the MD5 signature in the profile header.
+  Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
+  Test ZLIB_VERNUM instead of PNG_ZLIB_VERNUM in contrib/tools/pngfix.c
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CHANGES b/CHANGES
index b3e09f8..442d180 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4345,8 +4345,9 @@
     programs to generate and test a PNG which should have the problem.
 
 Version 1.6.0beta39 [January 19, 2013]
-  Again corrected attempt at overflow detection in png_set_unknown_chunks().
-  Added overflow detection in png_set_sPLT() and png_set_text_2().
+  Again corrected attempt at overflow detection in png_set_unknown_chunks()
+  (CVE-2013-7353).  Added overflow detection in png_set_sPLT() and
+  png_set_text_2() (CVE-2013-7354).
 
 Version 1.6.0beta40 [January 20, 2013]
   Use consistent handling of overflows in text, sPLT and unknown png_set_* APIs
@@ -4873,6 +4874,56 @@
   Un-deprecated png_data_freer().
 
 Version 1.6.10 [March 6, 2014]
+  No changes.
+
+Version 1.6.11beta01 [March 17, 2014]
+  Use "if (value != 0)" instead of "if (value)" consistently.
+  Changed ZlibSrcDir from 1.2.5 to 1.2.8 in projects/vstudio.
+  Moved configuration information from the manual to the INSTALL file.
+
+Version 1.6.11beta02 [April 6, 2014]
+  Removed #if/#else/#endif from inside two pow() calls in pngvalid.c because
+    they were handled improperly by Portland Group's PGI-14.1 - PGI-14.3
+    when using its "__builtin_pow()" function.
+  Silence 'unused parameter' build warnings (Cosmin Truta).
+  $(CP) is now used alongside $(RM_F).  Also, use 'copy' instead of 'cp'
+    where applicable, and applied other minor makefile changes (Cosmin).
+  Don't warn about invalid dimensions exceeding user limits (Cosmin).
+  Allow an easy replacement of the default pre-built configuration
+    header with a custom header, via the make PNGLIBCONF_H_PREBUILT
+    macro (Cosmin).
+
+Version 1.6.11beta03 [April 6, 2014]
+  Fixed a typo in pngrutil.c, introduced in libpng-1.5.6, that interferes
+    with "blocky" expansion of sub-8-bit interlaced PNG files (Eric Huss).
+  Optionally use  __builtin_bswap16() in png_do_swap().
+
+Version 1.6.11beta04 [April 19, 2014]
+  Made progressive reading of interlaced images consistent with the
+    behavior of the sequential reader and consistent with the manual, by
+    moving some code out of the PNG_READ_INTERLACING_SUPPORTED blocks. The
+    row_callback now receives the proper pass number and unexpanded rows, when
+    png_combine_row() isn't built or used, and png_set_interlace_handling()
+    is not called.
+  Allow PNG_sRGB_PROFILE_CHECKING = (-1) to mean no sRGB profile checking.
+
+Version 1.6.11beta05 [April 26, 2014]
+  Do not reject ICC V2 profiles that lack padding (Kai-Uwe Behrmann).
+  Relocated closing bracket of the sRGB profile test loop to avoid getting
+    "Not recognizing known sRGB profile that has been edited" warning for
+    ICC V2 profiles that lack the MD5 signature in the profile header.
+
+Version 1.6.11beta06 [May 19, 2014]
+  Added PNG_SKIP_sRGB_CHECK_PROFILE choice for png_set_option().
+
+Version 1.6.11rc01 [May 27, 2014]
+  No changes.
+
+Version 1.6.11rc02 [June 3, 2014]
+  Test ZLIB_VERNUM instead of PNG_ZLIB_VERNUM in contrib/tools/pngfix.c
+
+Version 1.6.11 [June 5, 2014]
+  No changes.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 34d62b5..6d6e901 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -16,7 +16,7 @@
 
 set(PNGLIB_MAJOR 1)
 set(PNGLIB_MINOR 6)
-set(PNGLIB_RELEASE 10)
+set(PNGLIB_RELEASE 11)
 set(PNGLIB_NAME libpng${PNGLIB_MAJOR}${PNGLIB_MINOR})
 set(PNGLIB_VERSION ${PNGLIB_MAJOR}.${PNGLIB_MINOR}.${PNGLIB_RELEASE})
 
@@ -252,7 +252,7 @@
 # SET UP LINKS
 if(PNG_SHARED)
   set_target_properties(${PNG_LIB_NAME} PROPERTIES
-#   VERSION 16.${PNGLIB_RELEASE}.1.6.10
+#   VERSION 16.${PNGLIB_RELEASE}.1.6.11
     VERSION 16.${PNGLIB_RELEASE}.0
     SOVERSION 16
     CLEAN_DIRECT_OUTPUT 1)
diff --git a/INSTALL b/INSTALL
index f987378..49e9329 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,6 +1,27 @@
 
 Installing libpng
 
+Contents
+
+   I. Simple installation
+  II. Rebuilding the configure scripts
+ III. Using scripts/makefile*
+  IV. Using cmake
+   V. Directory structure
+  VI. Building with project files
+ VII. Building with makefiles
+VIII. Configuring libpng for 16-bit platforms
+  IX. Configuring for DOS
+   X. Configuring for Medium Model
+  XI. Prepending a prefix to exported symbols
+ XII. Configuring for compiler xxx:
+XIII. Removing unwanted object code
+ XIV. Changes to the build and configuration of libpng in libpng-1.5.x
+  XV. Configuring libpng for multiprocessing
+ XVI. Other sources of information about libpng:
+
+I. Simple installation
+
 On Unix/Linux and similar systems, you can simply type
 
     ./configure [--prefix=/path]
@@ -9,6 +30,8 @@
 
 and ignore the rest of this document.
 
+II. Rebuilding the configure scripts
+
 If configure does not work on your system, or if you have a need to
 change configure.ac or Makefile.am, and you have a reasonably
 up-to-date set of tools, running ./autogen.sh in a git clone before
@@ -24,9 +47,12 @@
     make install
     make check
 
+III. Using scripts/makefile*
+
 Instead, you can use one of the custom-built makefiles in the
 "scripts" directory
 
+    cp scripts/pnglibconf.h.prebuilt pnglibconf.h
     cp scripts/makefile.system makefile
     make test
     make install
@@ -59,15 +85,19 @@
 If you are using one of the makefile scripts, put ZLIBLIB and ZLIBINC
 in your environment and type "make ZLIBLIB=$ZLIBLIB ZLIBINC=$ZLIBINC test".
 
+IV. Using cmake
+
 If you want to use "cmake" (see www.cmake.org), type
 
    cmake . -DCMAKE_INSTALL_PREFIX=/path
    make
    make install
 
+V. Directory structure
+
 You can rename the directories that you downloaded (they
-might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.7"
-or "zlib127") so that you have directories called "zlib" and "libpng".
+might be called "libpng-x.y.z" or "libpngNN" and "zlib-1.2.8"
+or "zlib128") so that you have directories called "zlib" and "libpng".
 
 Your directory structure should look like this:
 
@@ -110,6 +140,8 @@
 distribution of libpng.  It is available in both tar.gz (UNIX style line
 endings) and zip (DOS style line endings) formats.
 
+VI. Building with project files
+
 If you are building libpng with MSVC, you can enter the
 libpng projects\visualc6 or visualc71 directory and follow the instructions
 in README.txt.
@@ -118,11 +150,15 @@
 then come back here and run "configure" or choose the appropriate
 makefile.sys in the scripts directory.
 
+VII. Building with makefiles
+
 Copy the file (or files) that you need from the
 scripts directory into this directory, for example
 
    MSDOS example: copy scripts\makefile.msc makefile
-   UNIX example:    cp scripts/makefile.std makefile
+                  copy scripts\pnglibconf.h.prebuilt pnglibconf.h
+   UNIX example:  cp scripts/makefile.std makefile
+                  cp scripts/pnglibconf.h.prebuilt pnglibconf.h
 
 Read the makefile to see if you need to change any source or
 target directories to match your preferences.
@@ -145,6 +181,189 @@
 Some also allow you to run "make test-installed" after you have
 run "make install".
 
+VIII. Configuring libpng for 16-bit platforms
+
+You will want to look into zconf.h to tell zlib (and thus libpng) that
+it cannot allocate more then 64K at a time.  Even if you can, the memory
+won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
+
+IX. Configuring for DOS
+
+For DOS users who only have access to the lower 640K, you will
+have to limit zlib's memory usage via a png_set_compression_mem_level()
+call.  See zlib.h or zconf.h in the zlib library for more information.
+
+X. Configuring for Medium Model
+
+Libpng's support for medium model has been tested on most of the popular
+compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
+defined, and FAR gets defined to far in pngconf.h, and you should be
+all set.  Everything in the library (except for zlib's structure) is
+expecting far data.  You must use the typedefs with the p or pp on
+the end for pointers (or at least look at them and be careful).  Make
+note that the rows of data are defined as png_bytepp, which is
+an "unsigned char far * far *".
+
+XI. Prepending a prefix to exported symbols
+
+Starting with libpng-1.6.0, you can configure libpng (when using the
+"configure" script) to prefix all exported symbols by means of the
+configuration option "--with-libpng-prefix=FOO_", where FOO_ can be any
+string beginning with a letter and containing only uppercase
+and lowercase letters, digits, and the underscore (i.e., a C language
+identifier).  This creates a set of macros in pnglibconf.h, so this is
+transparent to applications; their function calls get transformed by
+the macros to use the modified names.
+
+XII. Configuring for compiler xxx:
+
+All includes for libpng are in pngconf.h.  If you need to add, change
+or delete an include, this is the place to do it.
+The includes that are not needed outside libpng are placed in pngpriv.h,
+which is only used by the routines inside libpng itself.
+The files in libpng proper only include pngpriv.h and png.h, which
+in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
+As of libpng-1.5.0, pngpriv.h also includes three other private header
+files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
+that previously appeared in the public headers.
+
+XIII. Removing unwanted object code
+
+There are a bunch of #define's in pngconf.h that control what parts of
+libpng are compiled.  All the defines end in _SUPPORTED.  If you are
+never going to use a capability, you can change the #define to #undef
+before recompiling libpng and save yourself code and data space, or
+you can turn off individual capabilities with defines that begin with
+PNG_NO_.
+
+In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
+
+You can also turn all of the transforms and ancillary chunk capabilities
+off en masse with compiler directives that define
+PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
+or all four, along with directives to turn on any of the capabilities that
+you do want.  The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the
+extra transformations but still leave the library fully capable of reading
+and writing PNG files with all known public chunks. Use of the
+PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
+that is incapable of reading or writing ancillary chunks.  If you are
+not using the progressive reading capability, you can turn that off
+with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
+capability, which you'll still have).
+
+All the reading and writing specific code are in separate files, so the
+linker should only grab the files it needs.  However, if you want to
+make sure, or if you are building a stand alone library, all the
+reading files start with "pngr" and all the writing files start with "pngw".
+The files that don't match either (like png.c, pngtrans.c, etc.)
+are used for both reading and writing, and always need to be included.
+The progressive reader is in pngpread.c
+
+If you are creating or distributing a dynamically linked library (a .so
+or DLL file), you should not remove or disable any parts of the library,
+as this will cause applications linked with different versions of the
+library to fail if they call functions not available in your library.
+The size of the library itself should not be an issue, because only
+those sections that are actually used will be loaded into memory.
+
+XIV. Changes to the build and configuration of libpng in libpng-1.5.x
+
+Details of internal changes to the library code can be found in the CHANGES
+file and in the GIT repository logs.  These will be of no concern to the vast
+majority of library users or builders; however, the few who configure libpng
+to a non-default feature set may need to change how this is done.
+
+There should be no need for library builders to alter build scripts if
+these use the distributed build support - configure or the makefiles -
+however, users of the makefiles may care to update their build scripts
+to build pnglibconf.h where the corresponding makefile does not do so.
+
+Building libpng with a non-default configuration has changed completely.
+The old method using pngusr.h should still work correctly even though the
+way pngusr.h is used in the build has been changed; however, library
+builders will probably want to examine the changes to take advantage of
+new capabilities and to simplify their build system.
+
+A. Specific changes to library configuration capabilities
+
+The exact mechanism used to control attributes of API functions has
+changed.  A single set of operating system independent macro definitions
+is used and operating system specific directives are defined in
+pnglibconf.h
+
+As part of this the mechanism used to choose procedure call standards on
+those systems that allow a choice has been changed.  At present this only
+affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems
+running on Intel processors.  As before, PNGAPI is defined where required
+to control the exported API functions; however, two new macros, PNGCBAPI
+and PNGCAPI, are used instead for callback functions (PNGCBAPI) and
+(PNGCAPI) for functions that must match a C library prototype (currently
+only png_longjmp_ptr, which must match the C longjmp function.)  The new
+approach is documented in pngconf.h
+
+Despite these changes, libpng 1.5.0 only supports the native C function
+calling standard on those platforms tested so far (__cdecl on Microsoft
+Windows).  This is because the support requirements for alternative
+calling conventions seem to no longer exist.  Developers who find it
+necessary to set PNG_API_RULE to 1 should advise the mailing list
+(png-mng-implement) of this and library builders who use Openwatcom and
+therefore set PNG_API_RULE to 2 should also contact the mailing list.
+
+B. Changes to the configuration mechanism
+
+Prior to libpng-1.5.0 library builders who needed to configure libpng
+had either to modify the exported pngconf.h header file to add system
+specific configuration or had to write feature selection macros into
+pngusr.h and cause this to be included into pngconf.h by defining
+PNG_USER_CONFIG. The latter mechanism had the disadvantage that an
+application built without PNG_USER_CONFIG defined would see the
+unmodified, default, libpng API and thus would probably fail to link.
+
+These mechanisms still work in the configure build and in any makefile
+build that builds pnglibconf.h, although the feature selection macros
+have changed somewhat as described above.  In 1.5.0, however, pngusr.h is
+processed only once, when the exported header file pnglibconf.h is built.
+pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
+build of pnglibconf.h and it is never included in an application build.
+
+The rarely used alternative of adding a list of feature macros to the
+CPPFLAGS setting in the build also still works; however, the macros will be
+copied to pnglibconf.h and this may produce macro redefinition warnings
+when the individual C files are compiled.
+
+All configuration now only works if pnglibconf.h is built from
+scripts/pnglibconf.dfa.  This requires the program awk.  Brian Kernighan
+(the original author of awk) maintains C source code of that awk and this
+and all known later implementations (often called by subtly different
+names - nawk and gawk for example) are adequate to build pnglibconf.h.
+The Sun Microsystems (now Oracle) program 'awk' is an earlier version
+and does not work; this may also apply to other systems that have a
+functioning awk called 'nawk'.
+
+Configuration options are now documented in scripts/pnglibconf.dfa.  This
+file also includes dependency information that ensures a configuration is
+consistent; that is, if a feature is switched off dependent features are
+also removed.  As a recommended alternative to using feature macros in
+pngusr.h a system builder may also define equivalent options in pngusr.dfa
+(or, indeed, any file) and add that to the configuration by setting
+DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
+how to do this, and a case where pngusr.h is still required.
+
+XV. Configuring libpng for multiprocessing
+
+Libpng uses setjmp()/longjmp() for error handling.  Unfortunately setjmp()
+is known to be not thread-safe on some platforms and we don't know of
+any platform where it is guaranteed to be thread-safe.  Therefore, if
+your application is going to be using multiple threads, you should
+configure libpng with PNG_NO_SETJMP in your pngusr.dfa file, with
+-DPNG_NO_SETJMP on your compile line, or with
+
+  #undef PNG_SETJMP_SUPPORTED
+
+in your pnglibconf.h or pngusr.h.
+
+XVI. Other sources of information about libpng:
+
 Further information can be found in the README and libpng-manual.txt
 files, in the individual makefiles, in png.h, and the manual pages
 libpng.3 and png.5.
diff --git a/LICENSE b/LICENSE
index 94f5e95..c6ac285 100644
--- a/LICENSE
+++ b/LICENSE
@@ -10,7 +10,7 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.10, March 6, 2014, are
+libpng versions 1.2.6, August 15, 2004, through 1.6.11, June 5, 2014, are
 Copyright (c) 2004, 2006-2014 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
@@ -108,4 +108,4 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 6, 2014
+June 5, 2014
diff --git a/README b/README
index 57f287b..639faa2 100644
--- a/README
+++ b/README
@@ -1,4 +1,4 @@
-README for libpng version 1.6.10 - March 6, 2014 (shared library 16.0)
+README for libpng version 1.6.11 - June 5, 2014 (shared library 16.0)
 See the note about version numbers near the top of png.h
 
 See INSTALL for instructions on how to install libpng.
diff --git a/TODO b/TODO
index 63613b8..7263377 100644
--- a/TODO
+++ b/TODO
@@ -6,6 +6,7 @@
 Fix problem with C++ and EXTERN "C".
 cHRM transformation.
 Remove setjmp/longjmp usage in favor of returning error codes.
+Palette creation.
 Add "grayscale->palette" transformation and "palette->grayscale" detection.
 Improved dithering.
 Multi-lingual error and warning message support.
diff --git a/arm/arm_init.c b/arm/arm_init.c
index 952b802..66b7da1 100644
--- a/arm/arm_init.c
+++ b/arm/arm_init.c
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2014 Glenn Randers-Pehrson
  * Written by Mans Rullgard, 2011.
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.10 [June 5, 2014]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -22,7 +22,7 @@
 /* WARNING: it is strongly recommended that you do not build libpng with
  * run-time checks for CPU features if at all possible.  In the case of the ARM
  * NEON instructions there is no processor-specific way of detecting the
- * presense of the required support, therefore run-time detectioon is extremely
+ * presence of the required support, therefore run-time detection is extremely
  * OS specific.
  *
  * You may set the macro PNG_ARM_NEON_FILE to the file name of file containing
diff --git a/configure.ac b/configure.ac
index a1ec129..8959c62 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,7 @@
 
 dnl Version number stuff here:
 
-AC_INIT([libpng],[1.6.10],[png-mng-implement@lists.sourceforge.net])
+AC_INIT([libpng],[1.6.11],[png-mng-implement@lists.sourceforge.net])
 AC_CONFIG_MACRO_DIR([scripts])
 
 # libpng does not follow GNU file name conventions (hence 'foreign')
@@ -39,10 +39,10 @@
 dnl AM_PREREQ([1.11.2])
 dnl stop configure from automagically running automake
 
-PNGLIB_VERSION=1.6.10
+PNGLIB_VERSION=1.6.11
 PNGLIB_MAJOR=1
 PNGLIB_MINOR=6
-PNGLIB_RELEASE=10
+PNGLIB_RELEASE=11
 
 dnl End of version number stuff
 
diff --git a/contrib/libtests/pngvalid.c b/contrib/libtests/pngvalid.c
index 788b693..e8401c9 100644
--- a/contrib/libtests/pngvalid.c
+++ b/contrib/libtests/pngvalid.c
@@ -386,9 +386,9 @@
 
    /* Palette images are restricted to 8 bit depth */
    if (*bit_depth <= 8
-#     ifdef DO_16BIT
+#ifdef DO_16BIT
          || (*colour_type != 3 && *bit_depth <= 16)
-#     endif
+#endif
       )
       return 1;
 
@@ -3155,10 +3155,10 @@
       for (; i<256; ++i)
          tRNS[i] = 24;
 
-#     ifdef PNG_WRITE_tRNS_SUPPORTED
+#  ifdef PNG_WRITE_tRNS_SUPPORTED
          if (j > 0)
             png_set_tRNS(pp, pi, tRNS, j, 0/*color*/);
-#     endif
+#  endif
    }
 }
 
@@ -6776,14 +6776,14 @@
           *  conversion adds another +/-2 in the 16-bit case and
           *  +/-(1<<(15-PNG_MAX_GAMMA_8)) in the 8-bit case.
           */
-         that->pm->limit += pow(
-#           if PNG_MAX_GAMMA_8 < 14
-               (that->this.bit_depth == 16 ? 8. :
-                  6. + (1<<(15-PNG_MAX_GAMMA_8)))
-#           else
-               8.
-#           endif
-               /65535, data.gamma);
+         that->pm->limit +=
+#        if PNG_MAX_GAMMA_8 < 14
+               pow((that->this.bit_depth == 16 ?
+                  8. : 6. + (1<<(15-PNG_MAX_GAMMA_8)))/65535, data.gamma);
+#        else
+               pow((that->this.bit_depth == 16 ?
+                  8. : 8. + (1<<(15-PNG_MAX_GAMMA_8)))/65535, data.gamma);
+#        endif
       }
 
       else
@@ -6801,13 +6801,12 @@
           * internal calculation errors, not the actual limit imposed by
           * pngvalid on the output errors.
           */
-         that->pm->limit += pow(
-#           if DIGITIZE
-               1.1
-#           else
-               1.
-#           endif
-               /255, data.gamma);
+         that->pm->limit +=
+#        if DIGITIZE
+             pow(1.1 /255, data.gamma);
+#        else
+             pow(1.0 /255, data.gamma);
+#        endif
       }
    }
 
diff --git a/contrib/pngminus/png2pnm.bat b/contrib/pngminus/png2pnm.bat
old mode 100644
new mode 100755
diff --git a/contrib/pngminus/png2pnm.sh b/contrib/pngminus/png2pnm.sh
old mode 100644
new mode 100755
diff --git a/contrib/pngminus/pngminus.bat b/contrib/pngminus/pngminus.bat
old mode 100644
new mode 100755
diff --git a/contrib/pngminus/pngminus.sh b/contrib/pngminus/pngminus.sh
old mode 100644
new mode 100755
diff --git a/contrib/pngminus/pnm2png.bat b/contrib/pngminus/pnm2png.bat
old mode 100644
new mode 100755
diff --git a/contrib/pngminus/pnm2png.sh b/contrib/pngminus/pnm2png.sh
old mode 100644
new mode 100755
diff --git a/contrib/tools/pngfix.c b/contrib/tools/pngfix.c
index 3b64627..068daf1 100644
--- a/contrib/tools/pngfix.c
+++ b/contrib/tools/pngfix.c
@@ -79,7 +79,7 @@
 #  error "pngfix not supported in this libpng version"
 #endif
 
-#if PNG_ZLIB_VERNUM >= 0x1240
+#if ZLIB_VERNUM >= 0x1240
 
 /* Copied from pngpriv.h */
 #ifdef __cplusplus
@@ -4014,16 +4014,16 @@
    return global_end(&global);
 }
 
-#else /* PNG_ZLIB_VERNUM < 0x1240 */
+#else /* ZLIB_VERNUM < 0x1240 */
 int
 main(void)
 {
    fprintf(stderr,
       "pngfix needs libpng with a zlib >=1.2.4 (not 0x%x)\n",
-      PNG_ZLIB_VERNUM);
+      ZLIB_VERNUM);
    return 77;
 }
-#endif /* PNG_ZLIB_VERNUM */
+#endif /* ZLIB_VERNUM */
 
 #else /* No read support */
 
diff --git a/example.c b/example.c
index 77d9077..ad5fc70 100644
--- a/example.c
+++ b/example.c
@@ -2,8 +2,8 @@
 #if 0 /* in case someone actually tries to compile this */
 
 /* example.c - an example of using libpng
- * Last changed in libpng 1.6.3 [July 18, 2013]
- * Maintained 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.11 [June 5, 2014]
+ * Maintained 1998-2014 Glenn Randers-Pehrson
  * Maintained 1996, 1997 Andreas Dilger)
  * Written 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  * To the extent possible under law, the authors have waived
@@ -970,7 +970,7 @@
    png_set_packswap(png_ptr);
 
    /* Turn on interlace handling if you are not using png_write_image() */
-   if (interlacing)
+   if (interlacing != 0)
       number_passes = png_set_interlace_handling(png_ptr);
 
    else
diff --git a/libpng-manual.txt b/libpng-manual.txt
index 73e09ab..b291ef1 100644
--- a/libpng-manual.txt
+++ b/libpng-manual.txt
@@ -1,6 +1,6 @@
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.10 - March 6, 2014
+ libpng version 1.6.11 - June 5, 2014
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2014 Glenn Randers-Pehrson
@@ -11,7 +11,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.10 - March 6, 2014
+ libpng versions 0.97, January 1998, through 1.6.11 - June 5, 2014
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2014 Glenn Randers-Pehrson
 
@@ -54,7 +54,7 @@
 file, example.c is a good starting point for using the library, as
 it is heavily commented and should include everything most people
 will need.  We assume that libpng is already installed; see the
-INSTALL file for instructions on how to install libpng.
+INSTALL file for instructions on how to configure and install libpng.
 
 For examples of libpng usage, see the files "example.c", "pngtest.c",
 and the files in the "contrib" directory, all of which are included in
@@ -2636,7 +2636,7 @@
         png_progressive_combine_row(png_ptr, old_row,
           new_row);
 
-    /* where old_row is what was displayed for
+    /* where old_row is what was displayed
        previously for the row.  Note that the first
        pass (pass == 0, really) will completely cover
        the old row, so the rows do not have to be
@@ -3793,8 +3793,9 @@
 The color/gray channels are not scaled (pre-multiplied) by the alpha
 channel and are suitable for passing to color management software.
 
-  b) As a value in the range 0..65535, contained in a 2-byte integer.  All
-channels can be converted to the original value by dividing by 65535; all
+  b) As a value in the range 0..65535, contained in a 2-byte integer, in
+the native byte order of the platform on which the application is running.
+All channels can be converted to the original value by dividing by 65535; all
 channels are linear.  Color channels use the RGB encoding (RGB end-points) of
 the sRGB specification.  This encoding is identified by the
 PNG_FORMAT_FLAG_LINEAR flag below.
@@ -3861,7 +3862,9 @@
 Then the linear 2-byte formats.  When naming these "Y" is used to
 indicate a luminance (gray) channel.  The component order within the pixel
 is always the same - there is no provision for swapping the order of the
-components in the linear format.
+components in the linear format.  The components are 16-bit integers in
+the native byte order for your platform, and there is no provision for
+swapping the bytes to a different endian condition.
 
    PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
    PNG_FORMAT_LINEAR_Y_ALPHA
@@ -3926,7 +3929,7 @@
     *
     * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
     *
-    * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+    * Alternatively, use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
     * information from one of the png_image_begin_read_ APIs and dynamically
     * allocate the required memory.
     */
@@ -3955,9 +3958,16 @@
    row.  For a color-mapped image this is the minimum number of bytes in a
    row.
 
+   If you need the stride measured in bytes, row_stride_bytes is
+   PNG_IMAGE_ROW_STRIDE(image) * PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)
+   plus any padding bytes that your application might need, for example
+   to start the next row on a 4-byte boundary.
+
   PNG_IMAGE_BUFFER_SIZE(image, row_stride)
     Returns the size, in bytes, of an image buffer given a png_image and a row
-    stride - the number of components to leave space for in each row.
+    stride - the number of components to leave space for in each row.  This
+    macro takes care of multiplying row_stride by PNG_IMAGE_PIXEL_COMONENT_SIZE
+    when the image has 2-byte components.
 
   PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB == 0x01
     This indicates the the RGB values of the in-memory bitmap do not
@@ -4086,14 +4096,11 @@
 is not the same as the calloc(number, size) function provided by stdlib.h.
 There is limited support for certain systems with segmented memory
 architectures and the types of pointers declared by png.h match this; you
-will have to use appropriate pointers in your application.  Since it is
-unlikely that the method of handling memory allocation on a platform
-will change between applications, these functions must be modified in
-the library at compile time.  If you prefer to use a different method
-of allocating and freeing data, you can use png_create_read_struct_2() or
-png_create_write_struct_2() to register your own functions as described
-above.  These functions also provide a void pointer that can be retrieved
-via
+will have to use appropriate pointers in your application.  If you prefer
+to use a different method of allocating and freeing data, you can use
+png_create_read_struct_2() or png_create_write_struct_2() to register your
+own functions as described above.  These functions also provide a void
+pointer that can be retrieved via
 
     mem_ptr=png_get_mem_ptr(png_ptr);
 
@@ -4236,29 +4243,6 @@
 transformation to the one you want to add and copy off of it.  More details
 can be found in the comments inside the code itself.
 
-Configuring for 16-bit platforms
-
-You will want to look into zconf.h to tell zlib (and thus libpng) that
-it cannot allocate more then 64K at a time.  Even if you can, the memory
-won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
-
-Configuring for DOS
-
-For DOS users who only have access to the lower 640K, you will
-have to limit zlib's memory usage via a png_set_compression_mem_level()
-call.  See zlib.h or zconf.h in the zlib library for more information.
-
-Configuring for Medium Model
-
-Libpng's support for medium model has been tested on most of the popular
-compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
-defined, and FAR gets defined to far in pngconf.h, and you should be
-all set.  Everything in the library (except for zlib's structure) is
-expecting far data.  You must use the typedefs with the p or pp on
-the end for pointers (or at least look at them and be careful).  Make
-note that the rows of data are defined as png_bytepp, which is
-an "unsigned char far * far *".
-
 Configuring for gui/windowing platforms:
 
 You will need to write new error and warning functions that use the GUI
@@ -4268,18 +4252,6 @@
 They can be changed later via png_set_error_fn().  On some compilers,
 you may also have to change the memory allocators (png_malloc, etc.).
 
-Configuring for compiler xxx:
-
-All includes for libpng are in pngconf.h.  If you need to add, change
-or delete an include, this is the place to do it.
-The includes that are not needed outside libpng are placed in pngpriv.h,
-which is only used by the routines inside libpng itself.
-The files in libpng proper only include pngpriv.h and png.h, which
-in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
-As of libpng-1.5.0, pngpriv.h also includes three other private header
-files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
-that previously appeared in the public headers.
-
 Configuring zlib:
 
 There are special functions to configure the compression.  Perhaps the
@@ -4321,6 +4293,8 @@
 
     png_set_compression_method(png_ptr, method);
 
+This controls the size of the IDAT chunks (default 8192):
+
     png_set_compression_buffer_size(png_ptr, size);
 
 As of libpng version 1.5.4, additional APIs became
@@ -4419,46 +4393,6 @@
 are given only to help explain the function usage.  Little testing has
 been done to find optimum values for either the costs or the weights.
 
-Removing unwanted object code
-
-There are a bunch of #define's in pngconf.h that control what parts of
-libpng are compiled.  All the defines end in _SUPPORTED.  If you are
-never going to use a capability, you can change the #define to #undef
-before recompiling libpng and save yourself code and data space, or
-you can turn off individual capabilities with defines that begin with
-PNG_NO_.
-
-In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
-
-You can also turn all of the transforms and ancillary chunk capabilities
-off en masse with compiler directives that define
-PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
-or all four,
-along with directives to turn on any of the capabilities that you do
-want.  The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra
-transformations but still leave the library fully capable of reading
-and writing PNG files with all known public chunks. Use of the
-PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
-that is incapable of reading or writing ancillary chunks.  If you are
-not using the progressive reading capability, you can turn that off
-with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
-capability, which you'll still have).
-
-All the reading and writing specific code are in separate files, so the
-linker should only grab the files it needs.  However, if you want to
-make sure, or if you are building a stand alone library, all the
-reading files start with "pngr" and all the writing files start with "pngw".
-The files that don't match either (like png.c, pngtrans.c, etc.)
-are used for both reading and writing, and always need to be included.
-The progressive reader is in pngpread.c
-
-If you are creating or distributing a dynamically linked library (a .so
-or DLL file), you should not remove or disable any parts of the library,
-as this will cause applications linked with different versions of the
-library to fail if they call functions not available in your library.
-The size of the library itself should not be an issue, because only
-those sections that are actually used will be loaded into memory.
-
 Requesting debug printout
 
 The macro definition PNG_DEBUG can be used to request debugging
@@ -4496,17 +4430,6 @@
 having level = 0 will be printed.  There aren't any such statements in
 this version of libpng, but if you insert some they will be printed.
 
-Prepending a prefix to exported symbols
-
-Starting with libpng-1.6.0, you can configure libpng (when using the
-"configure" script) to prefix all exported symbols by means of the
-configuration option "--with-libpng-prefix=FOO_", where FOO_ can be any
-string beginning with a letter and containing only uppercase
-and lowercase letters, digits, and the underscore (i.e., a C language
-identifier).  This creates a set of macros in pnglibconf.h, so this is
-transparent to applications; their function calls get transformed by
-the macros to use the modified names.
-
 VII.  MNG support
 
 The MNG specification (available at http://www.libpng.org/pub/mng) allows
@@ -4833,8 +4756,6 @@
 bKGD chunk; you must check those separately to determine the maximum
 palette index actually used.
 
-A. Changes that affect users of libpng
-
 There are no substantial API changes between the non-deprecated parts of
 the 1.4.5 API and the 1.5.0 API; however, the ability to directly access
 members of the main libpng control structures, png_struct and png_info,
@@ -4973,26 +4894,6 @@
 The png_set_option() function (and the "options" member of the png struct) was
 added to libpng-1.5.15.
 
-B. Changes to the build and configuration of libpng
-
-Details of internal changes to the library code can be found in the CHANGES
-file and in the GIT repository logs.  These will be of no concern to the vast
-majority of library users or builders; however, the few who configure libpng
-to a non-default feature set may need to change how this is done.
-
-There should be no need for library builders to alter build scripts if
-these use the distributed build support - configure or the makefiles -
-however, users of the makefiles may care to update their build scripts
-to build pnglibconf.h where the corresponding makefile does not do so.
-
-Building libpng with a non-default configuration has changed completely.
-The old method using pngusr.h should still work correctly even though the
-way pngusr.h is used in the build has been changed; however, library
-builders will probably want to examine the changes to take advantage of
-new capabilities and to simplify their build system.
-
-B.1 Specific changes to library configuration capabilities
-
 The library now supports a complete fixed point implementation and can
 thus be used on systems that have no floating point support or very
 limited or slow support.  Previously gamma correction, an essential part
@@ -5003,27 +4904,7 @@
 missing fixed point APIs have been implemented.
 
 The exact mechanism used to control attributes of API functions has
-changed.  A single set of operating system independent macro definitions
-is used and operating system specific directives are defined in
-pnglibconf.h
-
-As part of this the mechanism used to choose procedure call standards on
-those systems that allow a choice has been changed.  At present this only
-affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems
-running on Intel processors.  As before, PNGAPI is defined where required
-to control the exported API functions; however, two new macros, PNGCBAPI
-and PNGCAPI, are used instead for callback functions (PNGCBAPI) and
-(PNGCAPI) for functions that must match a C library prototype (currently
-only png_longjmp_ptr, which must match the C longjmp function.)  The new
-approach is documented in pngconf.h
-
-Despite these changes, libpng 1.5.0 only supports the native C function
-calling standard on those platforms tested so far (__cdecl on Microsoft
-Windows).  This is because the support requirements for alternative
-calling conventions seem to no longer exist.  Developers who find it
-necessary to set PNG_API_RULE to 1 should advise the mailing list
-(png-mng-implement) of this and library builders who use Openwatcom and
-therefore set PNG_API_RULE to 2 should also contact the mailing list.
+changed, as described in the INSTALL file.
 
 A new test program, pngvalid, is provided in addition to pngtest.
 pngvalid validates the arithmetic accuracy of the gamma correction
@@ -5099,46 +4980,6 @@
 to choose at app buildtime whether or not to use macros (previously
 impossible because the functions weren't in the default build.)
 
-B.2 Changes to the configuration mechanism
-
-Prior to libpng-1.5.0 library builders who needed to configure libpng
-had either to modify the exported pngconf.h header file to add system
-specific configuration or had to write feature selection macros into
-pngusr.h and cause this to be included into pngconf.h by defining
-PNG_USER_CONFIG. The latter mechanism had the disadvantage that an
-application built without PNG_USER_CONFIG defined would see the
-unmodified, default, libpng API and thus would probably fail to link.
-
-These mechanisms still work in the configure build and in any makefile
-build that builds pnglibconf.h, although the feature selection macros
-have changed somewhat as described above.  In 1.5.0, however, pngusr.h is
-processed only once, when the exported header file pnglibconf.h is built.
-pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
-build of pnglibconf.h and it is never included in an application build.
-
-The rarely used alternative of adding a list of feature macros to the
-CPPFLAGS setting in the build also still works; however, the macros will be
-copied to pnglibconf.h and this may produce macro redefinition warnings
-when the individual C files are compiled.
-
-All configuration now only works if pnglibconf.h is built from
-scripts/pnglibconf.dfa.  This requires the program awk.  Brian Kernighan
-(the original author of awk) maintains C source code of that awk and this
-and all known later implementations (often called by subtly different
-names - nawk and gawk for example) are adequate to build pnglibconf.h.
-The Sun Microsystems (now Oracle) program 'awk' is an earlier version
-and does not work; this may also apply to other systems that have a
-functioning awk called 'nawk'.
-
-Configuration options are now documented in scripts/pnglibconf.dfa.  This
-file also includes dependency information that ensures a configuration is
-consistent; that is, if a feature is switched off dependent features are
-also removed.  As a recommended alternative to using feature macros in
-pngusr.h a system builder may also define equivalent options in pngusr.dfa
-(or, indeed, any file) and add that to the configuration by setting
-DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
-how to do this, and a case where pngusr.h is still required.
-
 XII.  Changes to Libpng from version 1.5.x to 1.6.x
 
 A "simplified API" has been added (see documentation in png.h and a simple
@@ -5197,11 +5038,25 @@
 reader now does pretty complete validation of the basic format.  Some bad
 profiles that were previously accepted are now accepted with a warning or
 rejected, depending upon the png_set_benign_errors() setting, in particular the
-very old broken Microsoft/HP 3144-byte sRGB profile.  The PNG spec requirement
-that only grayscale profiles may appear in images with color type 0 or 4 and
-that even if the image only contains gray pixels, only RGB profiles may appear
-in images with color type 2, 3, or 6, is now enforced.  The sRGB chunk
-is allowed to appear in images with any color type.
+very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
+libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
+means of
+
+    #ifdef PNG_SKIP_sRGB_CHECK_PROFILE
+       png_set_option(ping, PNG_SKIP_sRGB_CHECK_PROFILE,
+           PNG_OPTION_ON);
+    #endif
+
+It's not a good idea to do this if you are using the "simplified API",
+which needs to be able to recognize an sRGB profile conveyed via the iCCP
+chunk.
+
+The PNG spec requirement that only grayscale profiles may appear in images
+with color type 0 or 4 and that even if the image only contains gray pixels,
+only RGB profiles may appear in images with color type 2, 3, or 6, is now
+enforced.  The sRGB chunk is allowed to appear in images with any color type
+and is interpreted by libpng to convey a one-tracer-curve profile or a
+three-tracer-curve profile as appropriate.
 
 Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
 an empty language field or an empty translated keyword.  Both of these
@@ -5235,16 +5090,16 @@
 stream to set the size of the sliding window for reading instead of using the
 default 32-kbyte sliding window size.  It was discovered that there are
 hundreds of PNG files in the wild that have incorrect CMF bytes that caused
-libpng to issue a "too far back" error and reject the file.  Libpng-1.6.3 and
-later calculate their own safe CMF from the image dimensions, provide a way
-to revert to the libpng-1.5.x behavior (ignoring the CMF bytes and using a
-32-kbyte sliding window), by using
+zlib to issue the "invalid distance too far back" error and reject the file.
+Libpng-1.6.3 and later calculate their own safe CMF from the image dimensions,
+provide a way to revert to the libpng-1.5.x behavior (ignoring the CMF bytes
+and using a 32-kbyte sliding window), by using
 
     png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW,
         PNG_OPTION_ON);
 
-and provide a tool (contrib/tools/pngfix) for optimizing the CMF bytes
-correctly.
+and provide a tool (contrib/tools/pngfix) for rewriting a PNG file while
+optimizing the CMF bytes in its IDAT chunk correctly.
 
 Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong
 length, which resulted in PNG files that cannot be read beyond the bad iTXt
@@ -5286,7 +5141,8 @@
 
 XV. Coding style
 
-Our coding style is similar to the "Allman" style, with curly
+Our coding style is similar to the "Allman" style
+(See http://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
 braces on separate lines:
 
     if (condition)
@@ -5408,6 +5264,9 @@
 We prefer to use underscores in variable names rather than camelCase, except
 for a few type names that we inherit from zlib.h.
 
+We prefer "if (something != 0)" and "if (something == 0)"
+over "if (something)" and if "(!something)", respectively.
+
 We do not use the TAB character for indentation in the C sources.
 
 Lines do not exceed 80 characters.
@@ -5416,13 +5275,13 @@
 
 XVI. Y2K Compliance in libpng
 
-March 6, 2014
+June 5, 2014
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.10 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.11 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer
diff --git a/libpng.3 b/libpng.3
index db4990f..79b5ac1 100644
--- a/libpng.3
+++ b/libpng.3
@@ -1,6 +1,6 @@
-.TH LIBPNG 3 "March 6, 2014"
+.TH LIBPNG 3 "June 5, 2014"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.10
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.11
 .SH SYNOPSIS
 \fB
 #include <png.h>\fP
@@ -504,7 +504,7 @@
 .SH LIBPNG.TXT
 libpng-manual.txt - A description on how to use and modify libpng
 
- libpng version 1.6.10 - March 6, 2014
+ libpng version 1.6.11 - June 5, 2014
  Updated and distributed by Glenn Randers-Pehrson
  <glennrp at users.sourceforge.net>
  Copyright (c) 1998-2014 Glenn Randers-Pehrson
@@ -515,7 +515,7 @@
 
  Based on:
 
- libpng versions 0.97, January 1998, through 1.6.10 - March 6, 2014
+ libpng versions 0.97, January 1998, through 1.6.11 - June 5, 2014
  Updated and distributed by Glenn Randers-Pehrson
  Copyright (c) 1998-2014 Glenn Randers-Pehrson
 
@@ -558,7 +558,7 @@
 file, example.c is a good starting point for using the library, as
 it is heavily commented and should include everything most people
 will need.  We assume that libpng is already installed; see the
-INSTALL file for instructions on how to install libpng.
+INSTALL file for instructions on how to configure and install libpng.
 
 For examples of libpng usage, see the files "example.c", "pngtest.c",
 and the files in the "contrib" directory, all of which are included in
@@ -3140,7 +3140,7 @@
         png_progressive_combine_row(png_ptr, old_row,
           new_row);
 
-    /* where old_row is what was displayed for
+    /* where old_row is what was displayed
        previously for the row.  Note that the first
        pass (pass == 0, really) will completely cover
        the old row, so the rows do not have to be
@@ -4297,8 +4297,9 @@
 The color/gray channels are not scaled (pre-multiplied) by the alpha
 channel and are suitable for passing to color management software.
 
-  b) As a value in the range 0..65535, contained in a 2-byte integer.  All
-channels can be converted to the original value by dividing by 65535; all
+  b) As a value in the range 0..65535, contained in a 2-byte integer, in
+the native byte order of the platform on which the application is running.
+All channels can be converted to the original value by dividing by 65535; all
 channels are linear.  Color channels use the RGB encoding (RGB end-points) of
 the sRGB specification.  This encoding is identified by the
 PNG_FORMAT_FLAG_LINEAR flag below.
@@ -4365,7 +4366,9 @@
 Then the linear 2-byte formats.  When naming these "Y" is used to
 indicate a luminance (gray) channel.  The component order within the pixel
 is always the same - there is no provision for swapping the order of the
-components in the linear format.
+components in the linear format.  The components are 16-bit integers in
+the native byte order for your platform, and there is no provision for
+swapping the bytes to a different endian condition.
 
    PNG_FORMAT_LINEAR_Y PNG_FORMAT_FLAG_LINEAR
    PNG_FORMAT_LINEAR_Y_ALPHA
@@ -4430,7 +4433,7 @@
     *
     * png_byte colormap[PNG_IMAGE_MAXIMUM_COLORMAP_COMPONENTS(sRGB_fmt)];
     *
-    * Alternatively use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
+    * Alternatively, use the PNG_IMAGE_COLORMAP_SIZE macro below to use the
     * information from one of the png_image_begin_read_ APIs and dynamically
     * allocate the required memory.
     */
@@ -4459,9 +4462,16 @@
    row.  For a color-mapped image this is the minimum number of bytes in a
    row.
 
+   If you need the stride measured in bytes, row_stride_bytes is
+   PNG_IMAGE_ROW_STRIDE(image) * PNG_IMAGE_PIXEL_COMPONENT_SIZE(fmt)
+   plus any padding bytes that your application might need, for example
+   to start the next row on a 4-byte boundary.
+
   PNG_IMAGE_BUFFER_SIZE(image, row_stride)
     Returns the size, in bytes, of an image buffer given a png_image and a row
-    stride - the number of components to leave space for in each row.
+    stride - the number of components to leave space for in each row.  This
+    macro takes care of multiplying row_stride by PNG_IMAGE_PIXEL_COMONENT_SIZE
+    when the image has 2-byte components.
 
   PNG_IMAGE_FLAG_COLORSPACE_NOT_sRGB == 0x01
     This indicates the the RGB values of the in-memory bitmap do not
@@ -4590,14 +4600,11 @@
 is not the same as the calloc(number, size) function provided by stdlib.h.
 There is limited support for certain systems with segmented memory
 architectures and the types of pointers declared by png.h match this; you
-will have to use appropriate pointers in your application.  Since it is
-unlikely that the method of handling memory allocation on a platform
-will change between applications, these functions must be modified in
-the library at compile time.  If you prefer to use a different method
-of allocating and freeing data, you can use png_create_read_struct_2() or
-png_create_write_struct_2() to register your own functions as described
-above.  These functions also provide a void pointer that can be retrieved
-via
+will have to use appropriate pointers in your application.  If you prefer
+to use a different method of allocating and freeing data, you can use
+png_create_read_struct_2() or png_create_write_struct_2() to register your
+own functions as described above.  These functions also provide a void
+pointer that can be retrieved via
 
     mem_ptr=png_get_mem_ptr(png_ptr);
 
@@ -4740,29 +4747,6 @@
 transformation to the one you want to add and copy off of it.  More details
 can be found in the comments inside the code itself.
 
-.SS Configuring for 16-bit platforms
-
-You will want to look into zconf.h to tell zlib (and thus libpng) that
-it cannot allocate more then 64K at a time.  Even if you can, the memory
-won't be accessible.  So limit zlib and libpng to 64K by defining MAXSEG_64K.
-
-.SS Configuring for DOS
-
-For DOS users who only have access to the lower 640K, you will
-have to limit zlib's memory usage via a png_set_compression_mem_level()
-call.  See zlib.h or zconf.h in the zlib library for more information.
-
-.SS Configuring for Medium Model
-
-Libpng's support for medium model has been tested on most of the popular
-compilers.  Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets
-defined, and FAR gets defined to far in pngconf.h, and you should be
-all set.  Everything in the library (except for zlib's structure) is
-expecting far data.  You must use the typedefs with the p or pp on
-the end for pointers (or at least look at them and be careful).  Make
-note that the rows of data are defined as png_bytepp, which is
-an "unsigned char far * far *".
-
 .SS Configuring for gui/windowing platforms:
 
 You will need to write new error and warning functions that use the GUI
@@ -4772,19 +4756,6 @@
 They can be changed later via png_set_error_fn().  On some compilers,
 you may also have to change the memory allocators (png_malloc, etc.).
 
-.SS Configuring for compiler xxx:
-
-All includes for libpng are in pngconf.h.  If you need to add, change
-or delete an include, this is the place to do it.
-The includes that are not needed outside libpng are placed in pngpriv.h,
-which is only used by the routines inside libpng itself.
-The files in libpng proper only include pngpriv.h and png.h, which
-%14%in turn includes pngconf.h.
-in turn includes pngconf.h and, as of libpng-1.5.0, pnglibconf.h.
-As of libpng-1.5.0, pngpriv.h also includes three other private header
-files, pngstruct.h, pnginfo.h, and pngdebug.h, which contain material
-that previously appeared in the public headers.
-
 .SS Configuring zlib:
 
 There are special functions to configure the compression.  Perhaps the
@@ -4826,6 +4797,8 @@
 
     png_set_compression_method(png_ptr, method);
 
+This controls the size of the IDAT chunks (default 8192):
+
     png_set_compression_buffer_size(png_ptr, size);
 
 As of libpng version 1.5.4, additional APIs became
@@ -4924,46 +4897,6 @@
 are given only to help explain the function usage.  Little testing has
 been done to find optimum values for either the costs or the weights.
 
-.SS Removing unwanted object code
-
-There are a bunch of #define's in pngconf.h that control what parts of
-libpng are compiled.  All the defines end in _SUPPORTED.  If you are
-never going to use a capability, you can change the #define to #undef
-before recompiling libpng and save yourself code and data space, or
-you can turn off individual capabilities with defines that begin with
-PNG_NO_.
-
-In libpng-1.5.0 and later, the #define's are in pnglibconf.h instead.
-
-You can also turn all of the transforms and ancillary chunk capabilities
-off en masse with compiler directives that define
-PNG_NO_READ[or WRITE]_TRANSFORMS, or PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS,
-or all four,
-along with directives to turn on any of the capabilities that you do
-want.  The PNG_NO_READ[or WRITE]_TRANSFORMS directives disable the extra
-transformations but still leave the library fully capable of reading
-and writing PNG files with all known public chunks. Use of the
-PNG_NO_READ[or WRITE]_ANCILLARY_CHUNKS directive produces a library
-that is incapable of reading or writing ancillary chunks.  If you are
-not using the progressive reading capability, you can turn that off
-with PNG_NO_PROGRESSIVE_READ (don't confuse this with the INTERLACING
-capability, which you'll still have).
-
-All the reading and writing specific code are in separate files, so the
-linker should only grab the files it needs.  However, if you want to
-make sure, or if you are building a stand alone library, all the
-reading files start with "pngr" and all the writing files start with "pngw".
-The files that don't match either (like png.c, pngtrans.c, etc.)
-are used for both reading and writing, and always need to be included.
-The progressive reader is in pngpread.c
-
-If you are creating or distributing a dynamically linked library (a .so
-or DLL file), you should not remove or disable any parts of the library,
-as this will cause applications linked with different versions of the
-library to fail if they call functions not available in your library.
-The size of the library itself should not be an issue, because only
-those sections that are actually used will be loaded into memory.
-
 .SS Requesting debug printout
 
 The macro definition PNG_DEBUG can be used to request debugging
@@ -5001,17 +4934,6 @@
 having level = 0 will be printed.  There aren't any such statements in
 this version of libpng, but if you insert some they will be printed.
 
-.SS Prepending a prefix to exported symbols
-
-Starting with libpng-1.6.0, you can configure libpng (when using the
-"configure" script) to prefix all exported symbols by means of the
-configuration option "\-\-with\-libpng\-prefix=FOO_", where FOO_ can be any
-string beginning with a letter and containing only uppercase
-and lowercase letters, digits, and the underscore (i.e., a C language
-identifier).  This creates a set of macros in pnglibconf.h, so this is
-transparent to applications; their function calls get transformed by
-the macros to use the modified names.
-
 .SH VII.  MNG support
 
 The MNG specification (available at http://www.libpng.org/pub/mng) allows
@@ -5338,8 +5260,6 @@
 bKGD chunk; you must check those separately to determine the maximum
 palette index actually used.
 
-A. Changes that affect users of libpng
-
 There are no substantial API changes between the non-deprecated parts of
 the 1.4.5 API and the 1.5.0 API; however, the ability to directly access
 members of the main libpng control structures, png_struct and png_info,
@@ -5478,26 +5398,6 @@
 The png_set_option() function (and the "options" member of the png struct) was
 added to libpng-1.5.15.
 
-B. Changes to the build and configuration of libpng
-
-Details of internal changes to the library code can be found in the CHANGES
-file and in the GIT repository logs.  These will be of no concern to the vast
-majority of library users or builders; however, the few who configure libpng
-to a non-default feature set may need to change how this is done.
-
-There should be no need for library builders to alter build scripts if
-these use the distributed build support - configure or the makefiles -
-however, users of the makefiles may care to update their build scripts
-to build pnglibconf.h where the corresponding makefile does not do so.
-
-Building libpng with a non-default configuration has changed completely.
-The old method using pngusr.h should still work correctly even though the
-way pngusr.h is used in the build has been changed; however, library
-builders will probably want to examine the changes to take advantage of
-new capabilities and to simplify their build system.
-
-B.1 Specific changes to library configuration capabilities
-
 The library now supports a complete fixed point implementation and can
 thus be used on systems that have no floating point support or very
 limited or slow support.  Previously gamma correction, an essential part
@@ -5508,27 +5408,7 @@
 missing fixed point APIs have been implemented.
 
 The exact mechanism used to control attributes of API functions has
-changed.  A single set of operating system independent macro definitions
-is used and operating system specific directives are defined in
-pnglibconf.h
-
-As part of this the mechanism used to choose procedure call standards on
-those systems that allow a choice has been changed.  At present this only
-affects certain Microsoft (DOS, Windows) and IBM (OS/2) operating systems
-running on Intel processors.  As before, PNGAPI is defined where required
-to control the exported API functions; however, two new macros, PNGCBAPI
-and PNGCAPI, are used instead for callback functions (PNGCBAPI) and
-(PNGCAPI) for functions that must match a C library prototype (currently
-only png_longjmp_ptr, which must match the C longjmp function.)  The new
-approach is documented in pngconf.h
-
-Despite these changes, libpng 1.5.0 only supports the native C function
-calling standard on those platforms tested so far (__cdecl on Microsoft
-Windows).  This is because the support requirements for alternative
-calling conventions seem to no longer exist.  Developers who find it
-necessary to set PNG_API_RULE to 1 should advise the mailing list
-(png-mng-implement) of this and library builders who use Openwatcom and
-therefore set PNG_API_RULE to 2 should also contact the mailing list.
+changed, as described in the INSTALL file.
 
 A new test program, pngvalid, is provided in addition to pngtest.
 pngvalid validates the arithmetic accuracy of the gamma correction
@@ -5604,46 +5484,6 @@
 to choose at app buildtime whether or not to use macros (previously
 impossible because the functions weren't in the default build.)
 
-B.2 Changes to the configuration mechanism
-
-Prior to libpng-1.5.0 library builders who needed to configure libpng
-had either to modify the exported pngconf.h header file to add system
-specific configuration or had to write feature selection macros into
-pngusr.h and cause this to be included into pngconf.h by defining
-PNG_USER_CONFIG. The latter mechanism had the disadvantage that an
-application built without PNG_USER_CONFIG defined would see the
-unmodified, default, libpng API and thus would probably fail to link.
-
-These mechanisms still work in the configure build and in any makefile
-build that builds pnglibconf.h, although the feature selection macros
-have changed somewhat as described above.  In 1.5.0, however, pngusr.h is
-processed only once, when the exported header file pnglibconf.h is built.
-pngconf.h no longer includes pngusr.h, therefore pngusr.h is ignored after the
-build of pnglibconf.h and it is never included in an application build.
-
-The rarely used alternative of adding a list of feature macros to the
-CPPFLAGS setting in the build also still works; however, the macros will be
-copied to pnglibconf.h and this may produce macro redefinition warnings
-when the individual C files are compiled.
-
-All configuration now only works if pnglibconf.h is built from
-scripts/pnglibconf.dfa.  This requires the program awk.  Brian Kernighan
-(the original author of awk) maintains C source code of that awk and this
-and all known later implementations (often called by subtly different
-names - nawk and gawk for example) are adequate to build pnglibconf.h.
-The Sun Microsystems (now Oracle) program 'awk' is an earlier version
-and does not work; this may also apply to other systems that have a
-functioning awk called 'nawk'.
-
-Configuration options are now documented in scripts/pnglibconf.dfa.  This
-file also includes dependency information that ensures a configuration is
-consistent; that is, if a feature is switched off dependent features are
-also removed.  As a recommended alternative to using feature macros in
-pngusr.h a system builder may also define equivalent options in pngusr.dfa
-(or, indeed, any file) and add that to the configuration by setting
-DFA_XTRA to the file name.  The makefiles in contrib/pngminim illustrate
-how to do this, and a case where pngusr.h is still required.
-
 .SH XII.  Changes to Libpng from version 1.5.x to 1.6.x
 
 A "simplified API" has been added (see documentation in png.h and a simple
@@ -5702,11 +5542,25 @@
 reader now does pretty complete validation of the basic format.  Some bad
 profiles that were previously accepted are now accepted with a warning or
 rejected, depending upon the png_set_benign_errors() setting, in particular the
-very old broken Microsoft/HP 3144-byte sRGB profile.  The PNG spec requirement
-that only grayscale profiles may appear in images with color type 0 or 4 and
-that even if the image only contains gray pixels, only RGB profiles may appear
-in images with color type 2, 3, or 6, is now enforced.  The sRGB chunk
-is allowed to appear in images with any color type.
+very old broken Microsoft/HP 3144-byte sRGB profile.  Starting with
+libpng-1.6.11, recognizing and checking sRGB profiles can be avoided by
+means of
+
+    #ifdef PNG_SKIP_sRGB_CHECK_PROFILE
+       png_set_option(ping, PNG_SKIP_sRGB_CHECK_PROFILE,
+           PNG_OPTION_ON);
+    #endif
+
+It's not a good idea to do this if you are using the "simplified API",
+which needs to be able to recognize an sRGB profile conveyed via the iCCP
+chunk.
+
+The PNG spec requirement that only grayscale profiles may appear in images
+with color type 0 or 4 and that even if the image only contains gray pixels,
+only RGB profiles may appear in images with color type 2, 3, or 6, is now
+enforced.  The sRGB chunk is allowed to appear in images with any color type
+and is interpreted by libpng to convey a one-tracer-curve profile or a
+three-tracer-curve profile as appropriate.
 
 Prior to libpng-1.6.0 a warning would be issued if the iTXt chunk contained
 an empty language field or an empty translated keyword.  Both of these
@@ -5740,16 +5594,16 @@
 stream to set the size of the sliding window for reading instead of using the
 default 32-kbyte sliding window size.  It was discovered that there are
 hundreds of PNG files in the wild that have incorrect CMF bytes that caused
-libpng to issue a "too far back" error and reject the file.  Libpng-1.6.3 and
-later calculate their own safe CMF from the image dimensions, provide a way
-to revert to the libpng-1.5.x behavior (ignoring the CMF bytes and using a
-32-kbyte sliding window), by using
+zlib to issue the "invalid distance too far back" error and reject the file.
+Libpng-1.6.3 and later calculate their own safe CMF from the image dimensions,
+provide a way to revert to the libpng-1.5.x behavior (ignoring the CMF bytes
+and using a 32-kbyte sliding window), by using
 
     png_set_option(png_ptr, PNG_MAXIMUM_INFLATE_WINDOW,
         PNG_OPTION_ON);
 
-and provide a tool (contrib/tools/pngfix) for optimizing the CMF bytes
-correctly.
+and provide a tool (contrib/tools/pngfix) for rewriting a PNG file while
+optimizing the CMF bytes in its IDAT chunk correctly.
 
 Libpng-1.6.0 and libpng-1.6.1 wrote uncompressed iTXt chunks with the wrong
 length, which resulted in PNG files that cannot be read beyond the bad iTXt
@@ -5791,7 +5645,8 @@
 
 .SH XV. Coding style
 
-Our coding style is similar to the "Allman" style, with curly
+Our coding style is similar to the "Allman" style
+(See http://en.wikipedia.org/wiki/Indent_style#Allman_style), with curly
 braces on separate lines:
 
     if (condition)
@@ -5913,6 +5768,9 @@
 We prefer to use underscores in variable names rather than camelCase, except
 for a few type names that we inherit from zlib.h.
 
+We prefer "if (something != 0)" and "if (something == 0)"
+over "if (something)" and if "(!something)", respectively.
+
 We do not use the TAB character for indentation in the C sources.
 
 Lines do not exceed 80 characters.
@@ -5921,13 +5779,13 @@
 
 .SH XVI. Y2K Compliance in libpng
 
-March 6, 2014
+June 5, 2014
 
 Since the PNG Development group is an ad-hoc body, we can't make
 an official declaration.
 
 This is your unofficial assurance that libpng from version 0.71 and
-upward through 1.6.10 are Y2K compliant.  It is my belief that earlier
+upward through 1.6.11 are Y2K compliant.  It is my belief that earlier
 versions were also Y2K compliant.
 
 Libpng only has two year fields.  One is a 2-byte unsigned integer
@@ -6159,8 +6017,11 @@
  1.6.9rc01-02        16    10609  16.so.16.9[.0]
  1.6.9               16    10609  16.so.16.9[.0]
  1.6.10beta01-03     16    10610  16.so.16.10[.0]
- 1.6.10rc01-04       16    10610  16.so.16.10[.0]
+ 1.6.10rc01-03       16    10610  16.so.16.10[.0]
  1.6.10              16    10610  16.so.16.10[.0]
+ 1.6.11beta01-06     16    10611  16.so.16.11[.0]
+ 1.6.11rc01-02       16    10611  16.so.16.11[.0]
+ 1.6.11              16    10611  16.so.16.11[.0]
 
 Henceforth the source version will match the shared-library minor
 and patch numbers; the shared-library major version number will be
@@ -6217,7 +6078,7 @@
 
 Thanks to Frank J. T. Wojcik for helping with the documentation.
 
-Libpng version 1.6.10 - March 6, 2014:
+Libpng version 1.6.11 - June 5, 2014:
 Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc.
 Currently maintained by Glenn Randers-Pehrson (glennrp at users.sourceforge.net).
 
@@ -6240,8 +6101,8 @@
 
 This code is released under the libpng license.
 
-libpng versions 1.2.6, August 15, 2004, through 1.6.10, March 6, 2014, are
-Copyright (c) 2004,2006-2007 Glenn Randers-Pehrson, and are
+libpng versions 1.2.6, August 15, 2004, through 1.6.11, June 5, 2014, are
+Copyright (c) 2004,2006-2014 Glenn Randers-Pehrson, and are
 distributed according to the same disclaimer and license as libpng-1.2.5
 with the following individual added to the list of Contributing Authors
 
@@ -6339,7 +6200,7 @@
 
 Glenn Randers-Pehrson
 glennrp at users.sourceforge.net
-March 6, 2014
+June 5, 2014
 
 .\" end of man page
 
diff --git a/libpngpf.3 b/libpngpf.3
index 844a9fc..bc60081 100644
--- a/libpngpf.3
+++ b/libpngpf.3
@@ -1,6 +1,6 @@
-.TH LIBPNGPF 3 "March 6, 2014"
+.TH LIBPNGPF 3 "June 5, 2014"
 .SH NAME
-libpng \- Portable Network Graphics (PNG) Reference Library 1.6.10
+libpng \- Portable Network Graphics (PNG) Reference Library 1.6.11
 (private functions)
 .SH SYNOPSIS
 \fB#include \fI"pngpriv.h"
diff --git a/png.5 b/png.5
index 3beacfa..df43f71 100644
--- a/png.5
+++ b/png.5
@@ -1,4 +1,4 @@
-.TH PNG 5 "March 6, 2014"
+.TH PNG 5 "June 5, 2014"
 .SH NAME
 png \- Portable Network Graphics (PNG) format
 .SH DESCRIPTION
diff --git a/png.c b/png.c
index 0cb4a1d..d4340d0 100644
--- a/png.c
+++ b/png.c
@@ -1,7 +1,7 @@
 
 /* png.c - location for general purpose libpng functions
  *
- * Last changed in libpng 1.6.9 [February 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -14,7 +14,7 @@
 #include "pngpriv.h"
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_10 Your_png_h_is_not_version_1_6_10;
+typedef png_libpng_version_1_6_11 Your_png_h_is_not_version_1_6_11;
 
 /* Tells libpng that we have already handled the first "num_bytes" bytes
  * of the PNG file signature.  If the PNG data is embedded into another
@@ -165,7 +165,7 @@
 int
 png_user_version_check(png_structrp png_ptr, png_const_charp user_png_ver)
 {
-   if (user_png_ver)
+   if (user_png_ver != NULL)
    {
       int i = 0;
 
@@ -773,13 +773,13 @@
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-     "libpng version 1.6.10 - March 6, 2014" PNG_STRING_NEWLINE \
+     "libpng version 1.6.11 - June 5, 2014" PNG_STRING_NEWLINE \
      "Copyright (c) 1998-2014 Glenn Randers-Pehrson" PNG_STRING_NEWLINE \
      "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
      "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
      PNG_STRING_NEWLINE;
 #  else
-      return "libpng version 1.6.10 - March 6, 2014\
+      return "libpng version 1.6.11 - June 5, 2014\
       Copyright (c) 1998-2014 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -1558,10 +1558,10 @@
 
    /* As a side-effect this routine also returns the XYZ endpoints. */
    result = png_XYZ_from_xy(XYZ, xy);
-   if (result) return result;
+   if (result != 0) return result;
 
    result = png_xy_from_XYZ(&xy_test, XYZ);
-   if (result) return result;
+   if (result != 0) return result;
 
    if (png_colorspace_endpoints_match(xy, &xy_test,
       5/*actually, the math is pretty accurate*/))
@@ -1581,10 +1581,10 @@
    png_XYZ XYZtemp;
 
    result = png_XYZ_normalize(XYZ);
-   if (result) return result;
+   if (result != 0) return result;
 
    result = png_xy_from_XYZ(xy, XYZ);
-   if (result) return result;
+   if (result != 0) return result;
 
    XYZtemp = *XYZ;
    return png_colorspace_check_xy(&XYZtemp, xy);
@@ -1625,7 +1625,7 @@
       }
 
       /* Only overwrite with preferred values */
-      if (!preferred)
+      if (preferred == 0)
          return 1; /* ok, but no change */
    }
 
@@ -1906,10 +1906,6 @@
       return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
          "too short");
 
-   if (profile_length & 3)
-      return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
-         "invalid length");
-
    return 1;
 }
 
@@ -1930,6 +1926,11 @@
       return png_icc_profile_error(png_ptr, colorspace, name, temp,
          "length does not match profile");
 
+   temp = (png_uint_32) (*(profile+8));
+   if (temp > 3 && (profile_length & 3))
+      return png_icc_profile_error(png_ptr, colorspace, name, profile_length,
+         "invalid length");
+
    temp = png_get_uint_32(profile+128); /* tag count: 12 bytes/tag */
    if (temp > 357913930 || /* (2^32-4-132)/12: maximum possible tag count */
       profile_length < 132+12*temp) /* truncated tag table */
@@ -2044,7 +2045,7 @@
             "invalid embedded Abstract ICC profile");
 
       case 0x6C696E6B: /* 'link' */
-         /* DeviceLink profiles cannnot be interpreted in a non-device specific
+         /* DeviceLink profiles cannot be interpreted in a non-device specific
           * fashion, if an app uses the AToB0Tag in the profile the results are
           * undefined unless the result is sent to the intended device,
           * therefore a DeviceLink profile should not be found embedded in a
@@ -2055,7 +2056,7 @@
 
       case 0x6E6D636C: /* 'nmcl' */
          /* A NamedColor profile is also device specific, however it doesn't
-          * contain an AToB0 tag that is open to misintrepretation.  Almost
+          * contain an AToB0 tag that is open to misinterpretation.  Almost
           * certainly it will fail the tests below.
           */
          (void)png_icc_profile_error(png_ptr, NULL, name, temp,
@@ -2136,7 +2137,7 @@
    return 1; /* success, maybe with warnings */
 }
 
-#ifdef PNG_sRGB_SUPPORTED
+#if defined(PNG_sRGB_SUPPORTED) && PNG_sRGB_PROFILE_CHECKS >= 0
 /* Information about the known ICC sRGB profiles */
 static const struct
 {
@@ -2210,11 +2211,18 @@
     * by sRGB (but maybe defined by a later ICC specification) the read of
     * the profile will fail at that point.
     */
+
+   /* First see if PNG_SKIP_sRGB_CHECK_PROFILE has been set to "on" */
+   if (((png_ptr->options >> PNG_SKIP_sRGB_CHECK_PROFILE) & 3) ==
+               PNG_OPTION_ON)
+   return 0;
+
    png_uint_32 length = 0;
    png_uint_32 intent = 0x10000; /* invalid */
 #if PNG_sRGB_PROFILE_CHECKS > 1
    uLong crc = 0; /* the value for 0 length data */
 #endif
+
    unsigned int i;
 
    for (i=0; i < (sizeof png_sRGB_checks) / (sizeof png_sRGB_checks[0]); ++i)
@@ -2294,7 +2302,6 @@
                   return 1+png_sRGB_checks[i].is_broken;
                }
             }
-         }
 
 # if PNG_sRGB_PROFILE_CHECKS > 0
          /* The signature matched, but the profile had been changed in some
@@ -2306,6 +2313,7 @@
              PNG_CHUNK_WARNING);
          break;
 # endif
+         }
       }
    }
 
@@ -2321,7 +2329,9 @@
    /* Is this profile one of the known ICC sRGB profiles?  If it is, just set
     * the sRGB information.
     */
+#if PNG_sRGB_PROFILE_CHECKS >= 0
    if (png_compare_ICC_profile_with_sRGB(png_ptr, profile, adler))
+#endif
       (void)png_colorspace_set_sRGB(png_ptr, colorspace,
          (int)/*already checked*/png_get_uint_32(profile+64));
 }
@@ -2435,45 +2445,46 @@
       png_warning(png_ptr, "Image width is zero in IHDR");
       error = 1;
    }
+   else if (width > PNG_UINT_31_MAX)
+   {
+      png_warning(png_ptr, "Invalid image width in IHDR");
+      error = 1;
+   }
+   else
+   {
+#     ifdef PNG_SET_USER_LIMITS_SUPPORTED
+      if (width > png_ptr->user_width_max)
+#     else
+      if (width > PNG_USER_WIDTH_MAX)
+#     endif
+      {
+         png_warning(png_ptr, "Image width exceeds user limit in IHDR");
+         error = 1;
+      }
+   }
 
    if (height == 0)
    {
       png_warning(png_ptr, "Image height is zero in IHDR");
       error = 1;
    }
-
-#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
-   if (width > png_ptr->user_width_max)
-
-#  else
-   if (width > PNG_USER_WIDTH_MAX)
-#  endif
-   {
-      png_warning(png_ptr, "Image width exceeds user limit in IHDR");
-      error = 1;
-   }
-
-#  ifdef PNG_SET_USER_LIMITS_SUPPORTED
-   if (height > png_ptr->user_height_max)
-#  else
-   if (height > PNG_USER_HEIGHT_MAX)
-#  endif
-   {
-      png_warning(png_ptr, "Image height exceeds user limit in IHDR");
-      error = 1;
-   }
-
-   if (width > PNG_UINT_31_MAX)
-   {
-      png_warning(png_ptr, "Invalid image width in IHDR");
-      error = 1;
-   }
-
-   if (height > PNG_UINT_31_MAX)
+   else if (height > PNG_UINT_31_MAX)
    {
       png_warning(png_ptr, "Invalid image height in IHDR");
       error = 1;
    }
+   else
+   {
+#     ifdef PNG_SET_USER_LIMITS_SUPPORTED
+      if (height > png_ptr->user_height_max)
+#     else
+      if (height > PNG_USER_HEIGHT_MAX)
+#     endif
+      {
+         png_warning(png_ptr, "Image height exceeds user limit in IHDR");
+         error = 1;
+      }
+   }
 
    /* Check other values */
    if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 &&
@@ -2738,7 +2749,7 @@
       }
       while (power > 0);
 
-      if (recip) d = 1/d;
+      if (recip != 0) d = 1/d;
    }
    /* else power is 0 and d is 1 */
 
@@ -3261,7 +3272,7 @@
             if (s00 >= (D >> 1))
                ++result;
 
-            if (negative)
+            if (negative != 0)
                result = -result;
 
             /* Check for overflow. */
@@ -3788,7 +3799,7 @@
                double d = floor(65535*pow(ig/(double)max, gamma_val*.00001)+.5);
                sub_table[j] = (png_uint_16)d;
 #           else
-               if (shift)
+               if (shift != 0)
                   ig = (ig * 65535U + max_by_2)/max;
 
                sub_table[j] = png_gamma_16bit_correct(ig, gamma_val);
@@ -3804,7 +3815,7 @@
          {
             png_uint_32 ig = (j << (8-shift)) + i;
 
-            if (shift)
+            if (shift != 0)
                ig = (ig * 65535U + max_by_2)/max;
 
             sub_table[j] = (png_uint_16)ig;
@@ -4092,7 +4103,7 @@
 }
 #endif /* READ_GAMMA */
 
-/* HARDWARE OPTION SUPPORT */
+/* HARDWARE OR SOFTWARE OPTION SUPPORT */
 #ifdef PNG_SET_OPTION_SUPPORTED
 int PNGAPI
 png_set_option(png_structrp png_ptr, int option, int onoff)
diff --git a/png.h b/png.h
index 16d3299..7d17a80 100644
--- a/png.h
+++ b/png.h
@@ -1,7 +1,7 @@
 
 /* png.h - header file for PNG reference library
  *
- * libpng version 1.6.10 - March 6, 2014
+ * libpng version 1.6.11 - June 5, 2014
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -11,7 +11,7 @@
  * Authors and maintainers:
  *   libpng versions 0.71, May 1995, through 0.88, January 1996: Guy Schalnat
  *   libpng versions 0.89c, June 1996, through 0.96, May 1997: Andreas Dilger
- *   libpng versions 0.97, January 1998, through 1.6.10 - March 6, 2014: Glenn
+ *   libpng versions 0.97, January 1998, through 1.6.11 - June 5, 2014: Glenn
  *   See also "Contributing Authors", below.
  *
  * Note about libpng version numbers:
@@ -193,8 +193,11 @@
  *    1.6.9rc01-02            16    10609  16.so.16.9[.0]
  *    1.6.9                   16    10609  16.so.16.9[.0]
  *    1.6.10beta01-03         16    10610  16.so.16.10[.0]
- *    1.6.10betarc01-04       16    10610  16.so.16.10[.0]
- *    1.6.10beta              16    10610  16.so.16.10[.0]
+ *    1.6.10rc01-03           16    10610  16.so.16.10[.0]
+ *    1.6.10                  16    10610  16.so.16.10[.0]
+ *    1.6.11beta01-06         16    10611  16.so.16.11[.0]
+ *    1.6.11rc01-02           16    10611  16.so.16.11[.0]
+ *    1.6.11                  16    10611  16.so.16.11[.0]
  *
  *   Henceforth the source version will match the shared-library major
  *   and minor numbers; the shared-library major version number will be
@@ -226,7 +229,7 @@
  *
  * This code is released under the libpng license.
  *
- * libpng versions 1.2.6, August 15, 2004, through 1.6.10, March 6, 2014, are
+ * libpng versions 1.2.6, August 15, 2004, through 1.6.11, June 5, 2014, are
  * Copyright (c) 2004, 2006-2013 Glenn Randers-Pehrson, and are
  * distributed according to the same disclaimer and license as libpng-1.2.5
  * with the following individual added to the list of Contributing Authors:
@@ -338,13 +341,13 @@
  * Y2K compliance in libpng:
  * =========================
  *
- *    March 6, 2014
+ *    June 5, 2014
  *
  *    Since the PNG Development group is an ad-hoc body, we can't make
  *    an official declaration.
  *
  *    This is your unofficial assurance that libpng from version 0.71 and
- *    upward through 1.6.10 are Y2K compliant.  It is my belief that
+ *    upward through 1.6.11 are Y2K compliant.  It is my belief that
  *    earlier versions were also Y2K compliant.
  *
  *    Libpng only has two year fields.  One is a 2-byte unsigned integer
@@ -397,16 +400,18 @@
 /* This is not the place to learn how to use libpng. The file libpng-manual.txt
  * describes how to use libpng, and the file example.c summarizes it
  * with some code on which to build.  This file is useful for looking
- * at the actual function definitions and structure components.
+ * at the actual function definitions and structure components.  If that
+ * file has been stripped from your copy of libpng, you can find it at
+ * <http://www.libpng.org/pub/png/libpng-manual.txt>
  *
  * If you just need to read a PNG file and don't want to read the documentation
  * skip to the end of this file and read the section entitled 'simplified API'.
  */
 
 /* Version information for png.h - this should match the version in png.c */
-#define PNG_LIBPNG_VER_STRING "1.6.10"
+#define PNG_LIBPNG_VER_STRING "1.6.11"
 #define PNG_HEADER_VERSION_STRING \
-     " libpng version 1.6.10 - March 6, 2014\n"
+     " libpng version 1.6.11 - June 5, 2014\n"
 
 #define PNG_LIBPNG_VER_SONUM   16
 #define PNG_LIBPNG_VER_DLLNUM  16
@@ -414,7 +419,7 @@
 /* These should match the first 3 components of PNG_LIBPNG_VER_STRING: */
 #define PNG_LIBPNG_VER_MAJOR   1
 #define PNG_LIBPNG_VER_MINOR   6
-#define PNG_LIBPNG_VER_RELEASE 10
+#define PNG_LIBPNG_VER_RELEASE 11
 
 /* This should match the numeric part of the final component of
  * PNG_LIBPNG_VER_STRING, omitting any leading zero:
@@ -445,7 +450,7 @@
  * version 1.0.0 was mis-numbered 100 instead of 10000).  From
  * version 1.0.1 it's    xxyyzz, where x=major, y=minor, z=release
  */
-#define PNG_LIBPNG_VER 10610 /* 1.6.10 */
+#define PNG_LIBPNG_VER 10611 /* 1.6.11 */
 
 /* Library configuration: these options cannot be changed after
  * the library has been built.
@@ -550,7 +555,7 @@
 /* This triggers a compiler error in png.c, if png.c and png.h
  * do not agree upon the version number.
  */
-typedef char* png_libpng_version_1_6_10;
+typedef char* png_libpng_version_1_6_11;
 
 /* Basic control structions.  Read libpng-manual.txt or libpng.3 for more info.
  *
@@ -1849,7 +1854,6 @@
  */
 PNG_EXPORT(220, png_uint_32, png_process_data_skip, (png_structrp));
 
-#ifdef PNG_READ_INTERLACING_SUPPORTED
 /* Function that combines rows.  'new_row' is a flag that should come from
  * the callback and be non-NULL if anything needs to be done; the library
  * stores its own version of the new data internally and ignores the passed
@@ -1857,7 +1861,6 @@
  */
 PNG_EXPORT(93, void, png_progressive_combine_row, (png_const_structrp png_ptr,
     png_bytep old_row, png_const_bytep new_row));
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */
 
 PNG_EXPORTA(94, png_voidp, png_malloc, (png_const_structrp png_ptr,
@@ -3225,7 +3228,8 @@
 #  define PNG_ARM_NEON   0 /* HARDWARE: ARM Neon SIMD instructions supported */
 #endif
 #define PNG_MAXIMUM_INFLATE_WINDOW 2 /* SOFTWARE: force maximum window */
-#define PNG_OPTION_NEXT  4 /* Next option - numbers must be even */
+#define PNG_SKIP_sRGB_CHECK_PROFILE 4 /* SOFTWARE: Check ICC profile for sRGB */
+#define PNG_OPTION_NEXT  6 /* Next option - numbers must be even */
 
 /* Return values: NOTE: there are four values and 'off' is *not* zero */
 #define PNG_OPTION_UNSET   0 /* Unset - defaults to off */
@@ -3238,7 +3242,7 @@
 #endif
 
 /*******************************************************************************
- *  END OF HARDWARE OPTIONS
+ *  END OF HARDWARE AND SOFTWARE OPTIONS
  ******************************************************************************/
 
 /* Maintainer: Put new public prototypes here ^, in libpng.3, and project
diff --git a/pngconf.h b/pngconf.h
index afc0ead..e61dfe6 100644
--- a/pngconf.h
+++ b/pngconf.h
@@ -1,7 +1,7 @@
 
 /* pngconf.h - machine configurable file for libpng
  *
- * libpng version 1.6.10 - March 6, 2014
+ * libpng version 1.6.11 - June 5, 2014
  *
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
diff --git a/pngerror.c b/pngerror.c
index 5876b47..03dcd7c 100644
--- a/pngerror.c
+++ b/pngerror.c
@@ -1,7 +1,7 @@
 
 /* pngerror.c - stub functions for i/o and memory allocation
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -195,7 +195,7 @@
           * drop the decimal point.  If the number is a true zero handle that
           * here.
           */
-         if (output)
+         if (output != 0)
             *--end = '.';
          else if (number == 0) /* and !output */
             *--end = '0';
@@ -759,6 +759,9 @@
 #ifdef PNG_SETJMP_SUPPORTED
    if (png_ptr && png_ptr->longjmp_fn && png_ptr->jmp_buf_ptr)
       png_ptr->longjmp_fn(*png_ptr->jmp_buf_ptr, val);
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(val)
 #endif
 
    /* If control reaches this point, png_longjmp() must not return. The only
@@ -939,7 +942,7 @@
    saved_error_buf = image->opaque->error_buf;
    result = setjmp(safe_jmpbuf) == 0;
 
-   if (result)
+   if (result != 0)
    {
 
       image->opaque->error_buf = safe_jmpbuf;
@@ -949,7 +952,7 @@
    image->opaque->error_buf = saved_error_buf;
 
    /* And do the cleanup prior to any failure return. */
-   if (!result)
+   if (result == 0)
       png_image_free(image);
 
    return result;
diff --git a/pngget.c b/pngget.c
index aca63a9..172f50a 100644
--- a/pngget.c
+++ b/pngget.c
@@ -1,8 +1,8 @@
 
 /* pngget.c - retrieval of values from info struct
  *
- * Last changed in libpng 1.6.1 [March 28, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.11 [June 5, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -124,6 +124,9 @@
          if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
             return (info_ptr->x_pixels_per_unit);
       }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -142,6 +145,9 @@
       if (info_ptr->phys_unit_type == PNG_RESOLUTION_METER)
          return (info_ptr->y_pixels_per_unit);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -159,6 +165,9 @@
           info_ptr->x_pixels_per_unit == info_ptr->y_pixels_per_unit)
          return (info_ptr->x_pixels_per_unit);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -229,6 +238,9 @@
       if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
          return (info_ptr->x_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -245,6 +257,9 @@
       if (info_ptr->offset_unit_type == PNG_OFFSET_MICROMETER)
          return (info_ptr->y_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -261,6 +276,9 @@
       if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
          return (info_ptr->x_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
@@ -277,6 +295,9 @@
       if (info_ptr->offset_unit_type == PNG_OFFSET_PIXEL)
          return (info_ptr->y_offset);
    }
+#else
+   PNG_UNUSED(png_ptr)
+   PNG_UNUSED(info_ptr)
 #endif
 
    return (0);
diff --git a/pngpread.c b/pngpread.c
index 6c8404e..a4d073b 100644
--- a/pngpread.c
+++ b/pngpread.c
@@ -1,7 +1,7 @@
 
 /* pngpread.c - read a png file in push mode
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -49,7 +49,7 @@
       /* It's easiest for the caller if we do the save, then the caller doesn't
        * have to supply the same data again:
        */
-      if (save)
+      if (save != 0)
          png_push_save_buffer(png_ptr);
       else
       {
@@ -979,15 +979,15 @@
 
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
-   /* Blow up interlaced rows to full size */
+   /* Expand interlaced rows to full size */
    if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE))
    {
       if (png_ptr->pass < 6)
          png_do_read_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass,
             png_ptr->transformations);
 
-    switch (png_ptr->pass)
-    {
+      switch (png_ptr->pass)
+      {
          case 0:
          {
             int i;
@@ -1154,7 +1154,6 @@
       }
    }
    else
-#endif
    {
       png_push_have_row(png_ptr, png_ptr->row_buf + 1);
       png_read_push_finish_row(png_ptr);
@@ -1164,7 +1163,6 @@
 void /* PRIVATE */
 png_read_push_finish_row(png_structrp png_ptr)
 {
-#ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
@@ -1189,7 +1187,6 @@
    if (png_ptr->row_number < png_ptr->num_rows)
       return;
 
-#ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
@@ -1224,7 +1221,6 @@
 
       } while (png_ptr->iwidth == 0 || png_ptr->num_rows == 0);
    }
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
 }
 
 void /* PRIVATE */
@@ -1249,7 +1245,6 @@
          (int)png_ptr->pass);
 }
 
-#ifdef PNG_READ_INTERLACING_SUPPORTED
 void PNGAPI
 png_progressive_combine_row(png_const_structrp png_ptr, png_bytep old_row,
     png_const_bytep new_row)
@@ -1262,9 +1257,8 @@
     * it must be png_ptr->row_buf+1
     */
    if (new_row != NULL)
-      png_combine_row(png_ptr, old_row, 1/*display*/);
+      png_combine_row(png_ptr, old_row, 1/*blocky display*/);
 }
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
 
 void PNGAPI
 png_set_progressive_read_fn(png_structrp png_ptr, png_voidp progressive_ptr,
diff --git a/pngpriv.h b/pngpriv.h
index a3fd1a4..c498313 100644
--- a/pngpriv.h
+++ b/pngpriv.h
@@ -6,7 +6,7 @@
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.10 [March 6, 1014]]
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ -822,7 +822,7 @@
     * zlib version number and because this affects handling of certain broken
     * PNG files the -I directives must match.
     *
-    * The most likely explanation is that you passed a -I in CFLAGS, this will
+    * The most likely explanation is that you passed a -I in CFLAGS. This will
     * not work; all the preprocessor directories and in particular all the -I
     * directives must be in CPPFLAGS.
     */
diff --git a/pngread.c b/pngread.c
index cd9ab58..356ac76 100644
--- a/pngread.c
+++ b/pngread.c
@@ -1,7 +1,7 @@
 
 /* pngread.c - read a PNG file
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -572,7 +572,7 @@
       png_error(png_ptr, "internal sequential row size calculation error");
 
 #ifdef PNG_READ_INTERLACING_SUPPORTED
-   /* Blow up interlaced rows to full size */
+   /* Expand interlaced rows to full size */
    if (png_ptr->interlaced &&
       (png_ptr->transformations & PNG_INTERLACE))
    {
@@ -1788,7 +1788,7 @@
    /* This is set if the color isn't gray but the output is. */
    if (encoding == P_LINEAR)
    {
-      if (convert_to_Y)
+      if (convert_to_Y != 0)
       {
          /* NOTE: these values are copied from png_do_rgb_to_gray */
          png_uint_32 y = (png_uint_32)6968 * red  + (png_uint_32)23434 * green +
@@ -3317,11 +3317,11 @@
  * PNG_COMPOSITE
  * PNG_GAMMA
  *
- * This is a work-round for the fact that both the PNG_RGB_TO_GRAY and
+ * This is a work-around for the fact that both the PNG_RGB_TO_GRAY and
  * PNG_COMPOSITE code performs gamma correction, so we get double gamma
- * correction.  The fix-up is to prevent the PNG_COMPOSITE operation happening
- * inside libpng, so this routine sees an 8 or 16-bit gray+alpha row and handles
- * the removal or pre-multiplication of the alpha channel.
+ * correction.  The fix-up is to prevent the PNG_COMPOSITE operation from
+ * happening inside libpng, so this routine sees an 8 or 16-bit gray+alpha
+ * row and handles the removal or pre-multiplication of the alpha channel.
  */
 static int
 png_image_read_background(png_voidp argument)
@@ -3586,7 +3586,7 @@
                         component = 0;
 
                      outrow[swap_alpha] = (png_uint_16)component;
-                     if (preserve_alpha)
+                     if (preserve_alpha != 0)
                         outrow[1 ^ swap_alpha] = alpha;
 
                      inrow += 2; /* components and alpha channel */
@@ -3679,7 +3679,7 @@
          png_set_alpha_mode_fixed(png_ptr, PNG_ALPHA_PNG, input_gamma_default);
       }
 
-      if (linear)
+      if (linear != 0)
       {
          /* If there *is* an alpha channel in the input it must be multiplied
           * out; use PNG_ALPHA_STANDARD, otherwise just use PNG_ALPHA_PNG.
@@ -3705,7 +3705,7 @@
        *
        * TODO: fix libpng and remove this.
        */
-      if (do_local_background)
+      if (do_local_background != 0)
       {
          png_fixed_point gtest;
 
@@ -3753,11 +3753,11 @@
              *
              * TODO: fix libpng and remove this.
              */
-            if (do_local_background)
+            if (do_local_background != 0)
                do_local_background = 2/*required*/;
 
             /* 16-bit output: just remove the channel */
-            else if (linear) /* compose on black (well, pre-multiply) */
+            else if (linear != 0) /* compose on black (well, pre-multiply) */
                png_set_strip_alpha(png_ptr);
 
             /* 8-bit output: do an appropriate compose */
@@ -3804,7 +3804,7 @@
             png_uint_32 filler; /* opaque filler */
             int where;
 
-            if (linear)
+            if (linear != 0)
                filler = 65535;
 
             else
@@ -3877,7 +3877,7 @@
       /* If the *output* is 16-bit then we need to check for a byte-swap on this
        * architecture.
        */
-      if (linear)
+      if (linear != 0)
       {
          PNG_CONST png_uint_16 le = 0x0001;
 
@@ -3886,7 +3886,7 @@
       }
 
       /* If change is not now 0 some transformation is missing - error out. */
-      if (change)
+      if (change != 0)
          png_error(png_ptr, "png_read_image: unsupported transformation");
    }
 
@@ -3898,7 +3898,7 @@
     *
     * TODO: remove the do_local_background fixup below.
     */
-   if (!do_local_compose && do_local_background != 2)
+   if (do_local_compose == 0 && do_local_background != 2)
       passes = png_set_interlace_handling(png_ptr);
 
    png_read_update_info(png_ptr, info_ptr);
@@ -3912,7 +3912,7 @@
       if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA)
       {
          /* do_local_compose removes this channel below. */
-         if (!do_local_compose)
+         if (do_local_compose == 0)
          {
             /* do_local_background does the same if required. */
             if (do_local_background != 2 ||
@@ -3921,7 +3921,7 @@
          }
       }
 
-      else if (do_local_compose) /* internal error */
+      else if (do_local_compose != 0) /* internal error */
          png_error(png_ptr, "png_image_read: alpha channel lost");
 
       if (info_ptr->bit_depth == 16)
@@ -3964,7 +3964,7 @@
       png_voidp first_row = display->buffer;
       ptrdiff_t row_bytes = display->row_stride;
 
-      if (linear)
+      if (linear != 0)
          row_bytes *= 2;
 
       /* The following expression is designed to work correctly whether it gives
@@ -3981,7 +3981,7 @@
       display->row_bytes = row_bytes;
    }
 
-   if (do_local_compose)
+   if (do_local_compose != 0)
    {
       int result;
       png_voidp row = png_malloc(png_ptr, png_get_rowbytes(png_ptr, info_ptr));
diff --git a/pngrtran.c b/pngrtran.c
index 5395396..d8ab705 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -143,7 +143,7 @@
    png_ptr->background = *background_color;
    png_ptr->background_gamma = background_gamma;
    png_ptr->background_gamma_type = (png_byte)(background_gamma_code);
-   if (need_expand)
+   if (need_expand != 0)
       png_ptr->transformations |= PNG_BACKGROUND_EXPAND;
    else
       png_ptr->transformations &= ~PNG_BACKGROUND_EXPAND;
@@ -226,7 +226,7 @@
 #     else
          PNG_UNUSED(png_ptr)
 #     endif
-      if (is_screen)
+      if (is_screen != 0)
          output_gamma = PNG_GAMMA_sRGB;
       else
          output_gamma = PNG_GAMMA_sRGB_INVERSE;
@@ -235,7 +235,7 @@
    else if (output_gamma == PNG_GAMMA_MAC_18 ||
       output_gamma == PNG_FP_1 / PNG_GAMMA_MAC_18)
    {
-      if (is_screen)
+      if (is_screen != 0)
          output_gamma = PNG_GAMMA_MAC_OLD;
       else
          output_gamma = PNG_GAMMA_MAC_INVERSE;
@@ -363,7 +363,7 @@
    /* Finally, if pre-multiplying, set the background fields to achieve the
     * desired result.
     */
-   if (compose)
+   if (compose != 0)
    {
       /* And obtain alpha pre-multiplication by composing on black: */
       memset(&png_ptr->background, 0, (sizeof png_ptr->background));
@@ -420,7 +420,7 @@
 
    png_ptr->transformations |= PNG_QUANTIZE;
 
-   if (!full_quantize)
+   if (full_quantize == 0)
    {
       int i;
 
@@ -475,12 +475,12 @@
                }
             }
 
-            if (done)
+            if (done != 0)
                break;
          }
 
          /* Swap the palette around, and set up a table, if necessary */
-         if (full_quantize)
+         if (full_quantize != 0)
          {
             int j = num_palette;
 
@@ -663,7 +663,7 @@
                         num_new_palette--;
                         palette[png_ptr->index_to_palette[j]]
                             = palette[num_new_palette];
-                        if (!full_quantize)
+                        if (full_quantize == 0)
                         {
                            int k;
 
@@ -731,7 +731,7 @@
    }
    png_ptr->num_palette = (png_uint_16)num_palette;
 
-   if (full_quantize)
+   if (full_quantize != 0)
    {
       int i;
       png_bytep distance;
@@ -1131,7 +1131,7 @@
    }
 
    /* If no alpha we can optimize. */
-   if (!input_has_alpha)
+   if (input_has_alpha == 0)
    {
       /* Any alpha means background and associative alpha processing is
        * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
@@ -1140,7 +1140,7 @@
       png_ptr->transformations &= ~PNG_ENCODE_ALPHA;
       png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
 
-      if (!input_has_transparency)
+      if (input_has_transparency == 0)
          png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
    }
 
@@ -1196,7 +1196,7 @@
    int input_has_transparency = png_ptr->num_trans > 0;
 
    /* If no alpha we can optimize. */
-   if (!input_has_alpha)
+   if (input_has_alpha == 0)
    {
       /* Any alpha means background and associative alpha processing is
        * required, however if the alpha is 0 or 1 throughout OPTIMIZE_ALPHA
@@ -1207,7 +1207,7 @@
          png_ptr->flags &= ~PNG_FLAG_OPTIMIZE_ALPHA;
 #     endif
 
-      if (!input_has_transparency)
+      if (input_has_transparency == 0)
          png_ptr->transformations &= ~(PNG_COMPOSE | PNG_BACKGROUND_EXPAND);
    }
 
@@ -1336,7 +1336,7 @@
        * the code immediately below if the transform can be handled outside the
        * row loop.
        */
-      if (gamma_correction)
+      if (gamma_correction != 0)
          png_ptr->transformations |= PNG_GAMMA;
 
       else
@@ -1743,11 +1743,11 @@
             g_sig = png_gamma_significant(g);
             gs_sig = png_gamma_significant(gs);
 
-            if (g_sig)
+            if (g_sig != 0)
                png_ptr->background_1.gray = png_gamma_correct(png_ptr,
                    png_ptr->background.gray, g);
 
-            if (gs_sig)
+            if (gs_sig != 0)
                png_ptr->background.gray = png_gamma_correct(png_ptr,
                    png_ptr->background.gray, gs);
 
@@ -1756,7 +1756,7 @@
                 (png_ptr->background.red != png_ptr->background.gray))
             {
                /* RGB or RGBA with color background */
-               if (g_sig)
+               if (g_sig != 0)
                {
                   png_ptr->background_1.red = png_gamma_correct(png_ptr,
                       png_ptr->background.red, g);
@@ -1768,7 +1768,7 @@
                       png_ptr->background.blue, g);
                }
 
-               if (gs_sig)
+               if (gs_sig != 0)
                {
                   png_ptr->background.red = png_gamma_correct(png_ptr,
                       png_ptr->background.red, gs);
@@ -2118,7 +2118,7 @@
    png_ptr->info_rowbytes = info_ptr->rowbytes;
 
 #ifndef PNG_READ_EXPAND_SUPPORTED
-   if (png_ptr)
+   if (png_ptr != NULL)
       return;
 #endif
 }
@@ -2277,7 +2277,7 @@
                have_shift = 1;
          }
 
-         if (!have_shift)
+         if (have_shift == 0)
             return;
       }
 
@@ -3038,7 +3038,7 @@
                   *(dp++) = red;
                }
 
-               if (have_alpha)
+               if (have_alpha != 0)
                   *(dp++) = *(sp++);
             }
          }
@@ -3067,7 +3067,7 @@
                else
                   *(dp++) = red;
 
-               if (have_alpha)
+               if (have_alpha != 0)
                   *(dp++) = *(sp++);
             }
          }
@@ -3119,7 +3119,7 @@
                *(dp++) = (png_byte)((w>>8) & 0xff);
                *(dp++) = (png_byte)(w & 0xff);
 
-               if (have_alpha)
+               if (have_alpha != 0)
                {
                   *(dp++) = *(sp++);
                   *(dp++) = *(sp++);
@@ -3153,7 +3153,7 @@
                *(dp++) = (png_byte)((gray16>>8) & 0xff);
                *(dp++) = (png_byte)(gray16 & 0xff);
 
-               if (have_alpha)
+               if (have_alpha != 0)
                {
                   *(dp++) = *(sp++);
                   *(dp++) = *(sp++);
@@ -3221,7 +3221,7 @@
                         *sp = (png_byte)(tmp & 0xff);
                      }
 
-                     if (!shift)
+                     if (shift == 0)
                      {
                         shift = 7;
                         sp++;
@@ -3260,7 +3260,7 @@
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 6;
                            sp++;
@@ -3286,7 +3286,7 @@
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 6;
                            sp++;
@@ -3326,7 +3326,7 @@
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 4;
                            sp++;
@@ -3352,7 +3352,7 @@
                            *sp = (png_byte)(tmp & 0xff);
                         }
 
-                        if (!shift)
+                        if (shift == 0)
                         {
                            shift = 4;
                            sp++;
@@ -3605,7 +3605,7 @@
 
                         v = gamma_to_1[*sp];
                         png_composite(w, v, a, png_ptr->background_1.gray);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_from_1[w];
                         *sp = w;
                      }
@@ -3662,7 +3662,7 @@
 
                         g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
                         png_composite_16(v, g, a, png_ptr->background_1.gray);
-                        if (optimize)
+                        if (optimize != 0)
                            w = v;
                         else
                            w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8];
@@ -3736,17 +3736,17 @@
 
                         v = gamma_to_1[*sp];
                         png_composite(w, v, a, png_ptr->background_1.red);
-                        if (!optimize) w = gamma_from_1[w];
+                        if (optimize == 0) w = gamma_from_1[w];
                         *sp = w;
 
                         v = gamma_to_1[*(sp + 1)];
                         png_composite(w, v, a, png_ptr->background_1.green);
-                        if (!optimize) w = gamma_from_1[w];
+                        if (optimize == 0) w = gamma_from_1[w];
                         *(sp + 1) = w;
 
                         v = gamma_to_1[*(sp + 2)];
                         png_composite(w, v, a, png_ptr->background_1.blue);
-                        if (!optimize) w = gamma_from_1[w];
+                        if (optimize == 0) w = gamma_from_1[w];
                         *(sp + 2) = w;
                      }
                   }
@@ -3828,7 +3828,7 @@
 
                         v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp];
                         png_composite_16(w, v, a, png_ptr->background_1.red);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
                                 8];
                         *sp = (png_byte)((w >> 8) & 0xff);
@@ -3836,7 +3836,7 @@
 
                         v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)];
                         png_composite_16(w, v, a, png_ptr->background_1.green);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
                                 8];
 
@@ -3845,7 +3845,7 @@
 
                         v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)];
                         png_composite_16(w, v, a, png_ptr->background_1.blue);
-                        if (!optimize)
+                        if (optimize == 0)
                            w = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >>
                                 8];
 
@@ -4763,7 +4763,7 @@
           png_do_rgb_to_gray(png_ptr, row_info,
               png_ptr->row_buf + 1);
 
-      if (rgb_error)
+      if (rgb_error != 0)
       {
          png_ptr->rgb_to_gray_status=1;
          if ((png_ptr->transformations & PNG_RGB_TO_GRAY) ==
diff --git a/pngrutil.c b/pngrutil.c
index 98e9524..fd7af38 100644
--- a/pngrutil.c
+++ b/pngrutil.c
@@ -1,7 +1,7 @@
 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -265,7 +265,7 @@
    /* The chunk CRC must be serialized in a single I/O call. */
    png_read_data(png_ptr, crc_bytes, 4);
 
-   if (need_crc)
+   if (need_crc != 0)
    {
       crc = png_get_uint_32(crc_bytes);
       return ((int)(crc != png_ptr->crc));
@@ -311,7 +311,7 @@
 
       else if (warn < 2) /* else silent */
       {
-         if (warn)
+         if (warn != 0)
              png_chunk_warning(png_ptr, "insufficient memory to read chunk");
 
          else
@@ -637,7 +637,7 @@
                   {
                      if (new_size == *newlength)
                      {
-                        if (terminate)
+                        if (terminate != 0)
                            text[prefix_size + *newlength] = 0;
 
                         if (prefix_size > 0)
@@ -1558,7 +1558,7 @@
       errmsg = "too many profiles";
 
    /* Failure: the reason is in 'errmsg' */
-   if (!finished)
+   if (finished == 0)
       png_crc_finish(png_ptr, length);
 
    png_ptr->colorspace.flags |= PNG_COLORSPACE_INVALID;
@@ -2672,7 +2672,7 @@
 
          buffer[uncompressed_length+prefix_length] = 0;
 
-         if (compressed)
+         if (compressed != 0)
             text.compression = PNG_ITXT_COMPRESSION_NONE;
 
          else
@@ -3153,7 +3153,7 @@
 #        define S_MASKS(d,s) { S_MASK(0,d,s), S_MASK(1,d,s), S_MASK(2,d,s),\
             S_MASK(3,d,s), S_MASK(4,d,s), S_MASK(5,d,s) }
 
-#        define B_MASKS(d,s) { B_MASK(1,d,s), S_MASK(3,d,s), S_MASK(5,d,s) }
+#        define B_MASKS(d,s) { B_MASK(1,d,s), B_MASK(3,d,s), B_MASK(5,d,s) }
 
 #        define DEPTH_INDEX(d) ((d)==1?0:((d)==2?1:2))
 
@@ -3192,7 +3192,7 @@
 #endif /* !PNG_USE_COMPILE_TIME_MASKS */
 
          /* Use the appropriate mask to copy the required bits.  In some cases
-          * the byte mask will be 0 or 0xff, optimize these cases.  row_width is
+          * the byte mask will be 0 or 0xff; optimize these cases.  row_width is
           * the number of pixels, but the code copies bytes, so it is necessary
           * to special case the end.
           */
@@ -3264,7 +3264,7 @@
          }
 
          /* Work out the bytes to copy. */
-         if (display)
+         if (display != 0)
          {
             /* When doing the 'block' algorithm the pixel in the pass gets
              * replicated to adjacent pixels.  This is why the even (0,2,4,6)
@@ -3464,7 +3464,7 @@
       /* Here if pixel_depth < 8 to check 'end_ptr' below. */
    }
    else
-#endif
+#endif /* PNG_READ_INTERLACING_SUPPORTED */
 
    /* If here then the switch above wasn't used so just memcpy the whole row
     * from the temporary row buffer (notice that this overwrites the end of the
@@ -4114,7 +4114,6 @@
 void /* PRIVATE */
 png_read_finish_row(png_structrp png_ptr)
 {
-#ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
@@ -4128,14 +4127,12 @@
 
    /* Offset to next interlace block in the y direction */
    static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
 
    png_debug(1, "in png_read_finish_row");
    png_ptr->row_number++;
    if (png_ptr->row_number < png_ptr->num_rows)
       return;
 
-#ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
       png_ptr->row_number = 0;
@@ -4173,7 +4170,6 @@
       if (png_ptr->pass < 7)
          return;
    }
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
 
    /* Here after at the end of the last row of the last pass. */
    png_read_finish_IDAT(png_ptr);
@@ -4183,7 +4179,6 @@
 void /* PRIVATE */
 png_read_start_row(png_structrp png_ptr)
 {
-#ifdef PNG_READ_INTERLACING_SUPPORTED
    /* Arrays to facilitate easy interlacing - use pass (0 - 6) as index */
 
    /* Start of interlace block */
@@ -4197,7 +4192,6 @@
 
    /* Offset to next interlace block in the y direction */
    static PNG_CONST png_byte png_pass_yinc[7] = {8, 8, 8, 4, 4, 2, 2};
-#endif
 
    int max_pixel_depth;
    png_size_t row_bytes;
@@ -4207,7 +4201,6 @@
 #ifdef PNG_READ_TRANSFORMS_SUPPORTED
    png_init_read_transformations(png_ptr);
 #endif
-#ifdef PNG_READ_INTERLACING_SUPPORTED
    if (png_ptr->interlaced)
    {
       if (!(png_ptr->transformations & PNG_INTERLACE))
@@ -4224,7 +4217,6 @@
    }
 
    else
-#endif /* PNG_READ_INTERLACING_SUPPORTED */
    {
       png_ptr->num_rows = png_ptr->height;
       png_ptr->iwidth = png_ptr->width;
diff --git a/pngset.c b/pngset.c
index fd718c9..cde4c6d 100644
--- a/pngset.c
+++ b/pngset.c
@@ -1,8 +1,8 @@
 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.6.8 [December 19, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.11 [June 5, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -637,7 +637,7 @@
       png_colorspace_sync_info(png_ptr, info_ptr);
 
       /* Don't do any of the copying if the profile was bad, or inconsistent. */
-      if (!result)
+      if (result == 0)
          return;
 
       /* But do write the gAMA and cHRM chunks from the profile. */
@@ -686,7 +686,7 @@
    int ret;
    ret = png_set_text_2(png_ptr, info_ptr, text_ptr, num_text);
 
-   if (ret)
+   if (ret != 0)
       png_error(png_ptr, "Insufficient memory to store text");
 }
 
@@ -855,7 +855,7 @@
          textp->text = textp->key + key_len + 1;
       }
 
-      if (text_length)
+      if (text_length != 0)
          memcpy(textp->text, text_ptr[i].text, text_length);
 
       *(textp->text + text_length) = '\0';
@@ -1353,7 +1353,7 @@
     * required because add_one_chunk above doesn't extend the list if the 'keep'
     * parameter is the default.
     */
-   if (keep)
+   if (keep != 0)
    {
       new_list = png_voidcast(png_bytep, png_malloc(png_ptr,
           5 * (num_chunks + old_num_chunks)));
@@ -1449,7 +1449,7 @@
 
    info_ptr->row_pointers = row_pointers;
 
-   if (row_pointers)
+   if (row_pointers != NULL)
       info_ptr->valid |= PNG_INFO_IDAT;
 }
 #endif
@@ -1536,7 +1536,7 @@
 void PNGAPI
 png_set_chunk_cache_max (png_structrp png_ptr, png_uint_32 user_chunk_cache_max)
 {
-    if (png_ptr)
+    if (png_ptr != NULL)
        png_ptr->user_chunk_cache_max = user_chunk_cache_max;
 }
 
@@ -1545,7 +1545,7 @@
 png_set_chunk_malloc_max (png_structrp png_ptr,
     png_alloc_size_t user_chunk_malloc_max)
 {
-   if (png_ptr)
+   if (png_ptr != NULL)
       png_ptr->user_chunk_malloc_max = user_chunk_malloc_max;
 }
 #endif /* ?PNG_SET_USER_LIMITS_SUPPORTED */
@@ -1563,7 +1563,7 @@
     * is the default behavior if png_set_benign_errors() is not called).
     */
 
-   if (allowed)
+   if (allowed != 0)
       png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN |
          PNG_FLAG_APP_WARNINGS_WARN | PNG_FLAG_APP_ERRORS_WARN;
 
diff --git a/pngtest.c b/pngtest.c
index 3b1f055..153a5ec 100644
--- a/pngtest.c
+++ b/pngtest.c
@@ -1,7 +1,7 @@
 
 /* pngtest.c - a simple test program to test libpng
  *
- * Last changed in libpng 1.6.9 [February 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -359,7 +359,7 @@
    default:
       err = 1;  /* uninitialized */
    }
-   if (err)
+   if (err != 0)
       png_error(png_ptr, "Bad I/O state or buffer size");
 }
 #endif
@@ -540,7 +540,7 @@
       /* Make sure the caller isn't assuming zeroed memory. */
       memset(pinfo->pointer, 0xdd, pinfo->size);
 
-      if (verbose)
+      if (verbose != 0)
          printf("png_malloc %lu bytes at %p\n", (unsigned long)size,
             pinfo->pointer);
 
@@ -580,7 +580,7 @@
             /* We must free the list element too, but first kill
                the memory that is to be freed. */
             memset(ptr, 0x55, pinfo->size);
-            if (pinfo)
+            if (pinfo != NULL)
                free(pinfo);
             pinfo = NULL;
             break;
@@ -597,10 +597,10 @@
    }
 
    /* Finally free the data. */
-   if (verbose)
+   if (verbose != 0)
       printf("Freeing %p\n", ptr);
 
-   if (ptr)
+   if (ptr != NULL)
       free(ptr);
    ptr = NULL;
 }
@@ -734,7 +734,7 @@
 {
    png_byte sTER[5] = {115,  84,  69,  82, '\0'};
 
-   if (verbose)
+   if (verbose != 0)
       fprintf(STDERR, "\n stereo mode = %d\n", user_chunk_data.sTER_mode);
 
    png_write_chunk(write_ptr, sTER, &user_chunk_data.sTER_mode, 1);
@@ -747,7 +747,7 @@
 
    png_byte vpag_chunk_data[9];
 
-   if (verbose)
+   if (verbose != 0)
       fprintf(STDERR, " vpAg = %lu x %lu, units = %d\n",
         (unsigned long)user_chunk_data.vpAg_width,
         (unsigned long)user_chunk_data.vpAg_height,
@@ -938,7 +938,7 @@
 #endif
 #endif
 
-   if (strict)
+   if (strict != 0)
    {
       /* Treat png_benign_error() as errors on read */
       png_set_benign_errors(read_ptr, 0);
@@ -954,7 +954,7 @@
        */
    }
 
-   else if (relaxed)
+   else if (relaxed != 0)
    {
       /* Allow application (pngtest) errors and warnings to pass */
       png_set_benign_errors(read_ptr, 1);
@@ -1254,7 +1254,7 @@
 
          pngtest_check_text_support(read_ptr, text_ptr, num_text);
 
-         if (verbose)
+         if (verbose != 0)
          {
             int i;
 
@@ -1320,7 +1320,7 @@
       int num_unknowns = png_get_unknown_chunks(read_ptr, read_info_ptr,
          &unknowns);
 
-      if (num_unknowns)
+      if (num_unknowns != 0)
       {
          png_set_unknown_chunks(write_ptr, write_info_ptr, unknowns,
            num_unknowns);
@@ -1436,7 +1436,7 @@
 
          pngtest_check_text_support(read_ptr, text_ptr, num_text);
 
-         if (verbose)
+         if (verbose != 0)
          {
             int i;
 
@@ -1480,7 +1480,7 @@
       int num_unknowns = png_get_unknown_chunks(read_ptr, end_info_ptr,
          &unknowns);
 
-      if (num_unknowns)
+      if (num_unknowns != 0)
       {
          png_set_unknown_chunks(write_ptr, write_end_info_ptr, unknowns,
            num_unknowns);
@@ -1521,7 +1521,7 @@
 #endif
 
 #ifdef PNG_EASY_ACCESS_SUPPORTED
-   if (verbose)
+   if (verbose != 0)
    {
       png_uint_32 iwidth, iheight;
       iwidth = png_get_image_width(write_ptr, write_info_ptr);
@@ -1599,7 +1599,7 @@
    }
 
 #ifdef PNG_WRITE_SUPPORTED /* else nothing was written */
-   if (interlace_preserved) /* else the files will be changed */
+   if (interlace_preserved != 0) /* else the files will be changed */
    {
       for (;;)
       {
@@ -1638,7 +1638,7 @@
               return (0);
          }
 
-         if (!num_in)
+         if (num_in == 0)
             break;
 
          if (memcmp(inbuf, outbuf, num_in))
@@ -1795,7 +1795,7 @@
      exit(1);
    }
 
-   if (multiple)
+   if (multiple != 0)
    {
       int i;
 #if defined(PNG_USER_MEM_SUPPORTED) && PNG_DEBUG
@@ -1991,4 +1991,4 @@
 #endif
 
 /* Generate a compiler error if there is an old png.h in the search path. */
-typedef png_libpng_version_1_6_10 Your_png_h_is_not_version_1_6_10;
+typedef png_libpng_version_1_6_11 Your_png_h_is_not_version_1_6_11;
diff --git a/pngtrans.c b/pngtrans.c
index 94f18df..9b6c3d0 100644
--- a/pngtrans.c
+++ b/pngtrans.c
@@ -1,7 +1,7 @@
 
 /* pngtrans.c - transforms the data in a row (used by both readers and writers)
  *
- * Last changed in libpng 1.6.9 [February 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -327,9 +327,16 @@
 
       for (i = 0; i < istop; i++, rp += 2)
       {
+#ifdef PNG_BUILTIN_BSWAP16_SUPPORTED
+         /* Feature added to libpng-1.6.11 for testing purposes, not
+          * enabled by default.
+          */
+         *(png_uint_16*)rp = __builtin_bswap16(*(png_uint_16*)rp);
+#else
          png_byte t = *rp;
          *rp = *(rp + 1);
          *(rp + 1) = t;
+#endif
       }
    }
 }
@@ -503,7 +510,7 @@
    {
       if (row_info->bit_depth == 8)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             ++sp;
          else          /* Skip initial channel and, for sp, the filler */
             sp += 2, ++dp;
@@ -517,7 +524,7 @@
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             sp += 2;
          else          /* Skip initial channel and, for sp, the filler */
             sp += 4, dp += 2;
@@ -543,7 +550,7 @@
    {
       if (row_info->bit_depth == 8)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             ++sp;
          else          /* Skip initial channels and, for sp, the filler */
             sp += 4, dp += 3;
@@ -557,7 +564,7 @@
 
       else if (row_info->bit_depth == 16)
       {
-         if (at_start) /* Skip initial filler */
+         if (at_start != 0) /* Skip initial filler */
             sp += 2;
          else          /* Skip initial channels and, for sp, the filler */
             sp += 8, dp += 6;
diff --git a/pngwrite.c b/pngwrite.c
index cff7864..f03aeb2 100644
--- a/pngwrite.c
+++ b/pngwrite.c
@@ -1,7 +1,7 @@
 
 /* pngwrite.c - general routines to write a PNG file
  *
- * Last changed in libpng 1.6.10 [March 6, 2014]
+ * Last changed in libpng 1.6.11 [June 5, 2014]
  * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -432,6 +432,7 @@
 
    /* Write end of PNG file */
    png_write_IEND(png_ptr);
+
    /* This flush, added in libpng-1.0.8, removed from libpng-1.0.9beta03,
     * and restored again in libpng-1.2.30, may cause some applications that
     * do not set png_ptr->output_flush_fn to crash.  If your application
@@ -479,7 +480,7 @@
 {
 #ifndef PNG_USER_MEM_SUPPORTED
    png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
-      error_fn, warn_fn, NULL, NULL, NULL);
+       error_fn, warn_fn, NULL, NULL, NULL);
 #else
    return png_create_write_struct_2(user_png_ver, error_ptr, error_fn,
        warn_fn, NULL, NULL, NULL);
@@ -492,7 +493,7 @@
     png_malloc_ptr malloc_fn, png_free_ptr free_fn),PNG_ALLOCATED)
 {
    png_structrp png_ptr = png_create_png_struct(user_png_ver, error_ptr,
-      error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
+       error_fn, warn_fn, mem_ptr, malloc_fn, free_fn);
 #endif /* PNG_USER_MEM_SUPPORTED */
    if (png_ptr != NULL)
    {
@@ -525,10 +526,10 @@
        * applications that must not fail to write at all costs!
        */
 #ifdef PNG_BENIGN_WRITE_ERRORS_SUPPORTED
-      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
       /* In stable builds only warn if an application error can be completely
        * handled.
        */
+      png_ptr->flags |= PNG_FLAG_BENIGN_ERRORS_WARN;
 #endif
 
       /* App warnings are warnings in release (or release candidate) builds but
@@ -826,7 +827,7 @@
    {
       png_do_write_interlace(&row_info, png_ptr->row_buf + 1, png_ptr->pass);
       /* This should always get caught above, but still ... */
-      if (!(row_info.width))
+      if (row_info.width == 0)
       {
          png_write_finish_row(png_ptr);
          return;
@@ -2177,7 +2178,7 @@
     * write an interlaced image.
     */
 
-   if (write_16bit)
+   if (write_16bit != 0)
    {
       /* The gamma here is 1.0 (linear) and the cHRM chunk matches sRGB. */
       png_set_gAMA_fixed(png_ptr, info_ptr, PNG_GAMMA_LINEAR);
@@ -2209,7 +2210,7 @@
     *
     * First check for a little endian system if writing 16 bit files.
     */
-   if (write_16bit)
+   if (write_16bit != 0)
    {
       PNG_CONST png_uint_16 le = 0x0001;
 
@@ -2250,7 +2251,7 @@
       png_const_bytep row = png_voidcast(png_const_bytep, display->buffer);
       ptrdiff_t row_bytes = display->row_stride;
 
-      if (linear)
+      if (linear != 0)
          row_bytes *= (sizeof (png_uint_16));
 
       if (row_bytes < 0)
@@ -2283,7 +2284,7 @@
       int result;
 
       display->local_row = row;
-      if (write_16bit)
+      if (write_16bit != 0)
          result = png_safe_execute(image, png_write_image_16bit, display);
       else
          result = png_safe_execute(image, png_write_image_8bit, display);
@@ -2292,7 +2293,7 @@
       png_free(png_ptr, row);
 
       /* Skip the 'write_end' on error: */
-      if (!result)
+      if (result == 0)
          return 0;
    }
 
diff --git a/pngwutil.c b/pngwutil.c
index 755bbdb..8a0b7f2 100644
--- a/pngwutil.c
+++ b/pngwutil.c
@@ -1,8 +1,8 @@
 
 /* pngwutil.c - utilities to write a PNG file
  *
- * Last changed in libpng 1.6.2 [April 25, 2013]
- * Copyright (c) 1998-2013 Glenn Randers-Pehrson
+ * Last changed in libpng 1.6.11 [June 5, 2014]
+ * Copyright (c) 1998-2014 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
  *
@@ -699,7 +699,7 @@
       if ((ch > 32 && ch <= 126) || (ch >= 161 /*&& ch <= 255*/))
          *new_key++ = ch, ++key_len, space = 0;
 
-      else if (!space)
+      else if (space == 0)
       {
          /* A space or an invalid character when one wasn't seen immediately
           * before; output just a space.
@@ -711,14 +711,14 @@
             bad_character = ch;
       }
 
-      else if (!bad_character)
+      else if (bad_character == 0)
          bad_character = ch; /* just skip it, record the first error */
    }
 
    if (key_len > 0 && space) /* trailing space */
    {
       --key_len, --new_key;
-      if (!bad_character)
+      if (bad_character == 0)
          bad_character = 32;
    }
 
@@ -732,7 +732,7 @@
    if (*key) /* keyword too long */
       png_warning(png_ptr, "keyword truncated");
 
-   else if (bad_character)
+   else if (bad_character != 0)
    {
       PNG_WARNING_PARAMETERS(p)
 
@@ -898,7 +898,7 @@
    /* Write the chunk */
    png_write_complete_chunk(png_ptr, png_IHDR, buf, (png_size_t)13);
 
-   if (!(png_ptr->do_filter))
+   if ((png_ptr->do_filter) == PNG_NO_FILTERS)
    {
       if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE ||
           png_ptr->bit_depth < 8)
@@ -1193,6 +1193,7 @@
    png_uint_32 profile_len;
    png_byte new_name[81]; /* 1 byte for the compression byte */
    compression_state comp;
+   png_uint_32 temp;
 
    png_debug(1, "in png_write_iCCP");
 
@@ -1207,7 +1208,8 @@
    if (profile_len < 132)
       png_error(png_ptr, "ICC profile too short");
 
-   if (profile_len & 0x03)
+   temp = (png_uint_32) (*(profile+8));
+   if (temp > 3 && (profile_len & 0x03))
       png_error(png_ptr, "ICC profile length invalid (not a multiple of 4)");
 
    {
@@ -1608,7 +1610,7 @@
     */
    png_write_chunk_data(png_ptr, new_key, key_len + 1);
 
-   if (text_len)
+   if (text_len != 0)
       png_write_chunk_data(png_ptr, (png_const_bytep)text, text_len);
 
    png_write_chunk_end(png_ptr);
@@ -1734,7 +1736,7 @@
 
    png_text_compress_init(&comp, (png_const_bytep)text, strlen(text));
 
-   if (compression)
+   if (compression != 0)
    {
       if (png_text_compress(png_ptr, png_iTXt, &comp, prefix_len) != Z_OK)
          png_error(png_ptr, png_ptr->zstream.msg);
@@ -1757,7 +1759,7 @@
 
    png_write_chunk_data(png_ptr, (png_const_bytep)lang_key, lang_key_len);
 
-   if (compression)
+   if (compression != 0)
       png_write_compressed_data_out(png_ptr, &comp);
 
    else
diff --git a/projects/vstudio/readme.txt b/projects/vstudio/readme.txt
index 2ee18ff..eca9924 100644
--- a/projects/vstudio/readme.txt
+++ b/projects/vstudio/readme.txt
@@ -1,7 +1,7 @@
 
 VisualStudio instructions
 
-libpng version 1.6.10 - March 6, 2014
+libpng version 1.6.11 - June 5, 2014
 
 Copyright (c) 1998-2010 Glenn Randers-Pehrson
 
diff --git a/projects/vstudio/zlib.props b/projects/vstudio/zlib.props
index 8438f36..a6e33f0 100644
--- a/projects/vstudio/zlib.props
+++ b/projects/vstudio/zlib.props
@@ -2,7 +2,7 @@
 <!--
  * zlib.props - location of zlib source
  *
- * libpng version 1.6.10 - March 6, 2014
+ * libpng version 1.6.11 - June 5, 2014
  *
  * Copyright (c) 1998-2011 Glenn Randers-Pehrson
  *
@@ -24,7 +24,7 @@
 	 source.
 
 	 If you use a relative directory name (as below) then it must be
-	 relative to the project directories; these are one level deepers than
+	 relative to the project directories; these are one level deeper than
 	 the directories containing this file.
 
 	 If the version of zlib you use does not match that used when the
@@ -32,7 +32,7 @@
 	 versions do not match.  The zlib version used in this build is recorded
 	 below:
      -->
-    <ZLibSrcDir>..\..\..\..\zlib-1.2.5</ZLibSrcDir>
+    <ZLibSrcDir>..\..\..\..\zlib-1.2.8</ZLibSrcDir>
 
     <!-- The following line allows compilation for an ARM target with Visual
          Studio 2012.  Notice that this is not supported by the Visual Studio
diff --git a/scripts/README.txt b/scripts/README.txt
index c468d97..68c3415 100644
--- a/scripts/README.txt
+++ b/scripts/README.txt
@@ -1,9 +1,9 @@
 
-Makefiles for  libpng version 1.6.10 - March 6, 2014
+Makefiles for  libpng version 1.6.11 - June 5, 2014
 
 pnglibconf.h.prebuilt       =>  Stores configuration settings
  makefile.linux    =>  Linux/ELF makefile
-                       (gcc, creates libpng16.so.16.1.6.10)
+                       (gcc, creates libpng16.so.16.1.6.11)
  makefile.gcc      =>  Generic makefile (gcc, creates static libpng.a)
  makefile.knr      =>  Archaic UNIX Makefile that converts files with
                        ansi2knr (Requires ansi2knr.c from
@@ -20,7 +20,7 @@
  makefile.dec      =>  DEC Alpha UNIX makefile
  makefile.dj2      =>  DJGPP 2 makefile
  makefile.elf      =>  Linux/ELF makefile symbol versioning,
-                       (gcc, creates libpng16.so.16.1.6.10)
+                       (gcc, creates libpng16.so.16.1.6.11)
  makefile.freebsd  =>  FreeBSD makefile
  makefile.gcc      =>  Generic gcc makefile
  makefile.hpgcc    =>  HPUX makefile using gcc
@@ -35,12 +35,12 @@
  makefile.os2      =>  OS/2 Makefile (gcc and emx, requires libpng.def)
  makefile.sco      =>  For SCO OSr5  ELF and Unixware 7 with Native cc
  makefile.sggcc    =>  Silicon Graphics (gcc,
-                       creates libpng16.so.16.1.6.10)
+                       creates libpng16.so.16.1.6.11)
  makefile.sgi      =>  Silicon Graphics IRIX makefile (cc, creates static lib)
  makefile.solaris  =>  Solaris 2.X makefile (gcc,
-                       creates libpng16.so.16.1.6.10)
+                       creates libpng16.so.16.1.6.11)
  makefile.so9      =>  Solaris 9 makefile (gcc,
-                       creates libpng16.so.16.1.6.10)
+                       creates libpng16.so.16.1.6.11)
  makefile.std      =>  Generic UNIX makefile (cc, creates static libpng.a)
  makefile.sunos    =>  Sun makefile
  makefile.32sunu   =>  Sun Ultra 32-bit makefile
diff --git a/scripts/def.dfn b/scripts/def.dfn
index c4b5a38..0b1c357 100644
--- a/scripts/def.dfn
+++ b/scripts/def.dfn
@@ -21,7 +21,7 @@
 PNG_DFN "OS2 CODE PRELOAD MOVEABLE DISCARDABLE"
 PNG_DFN ""
 PNG_DFN "EXPORTS"
-PNG_DFN ";Version 1.6.10"
+PNG_DFN ";Version 1.6.11"
 
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\
         PNG_DFN "@" SYMBOL_PREFIX "@@" name "@"
diff --git a/scripts/dfn.awk b/scripts/dfn.awk
old mode 100644
new mode 100755
Binary files differ
diff --git a/scripts/libpng-config-body.in b/scripts/libpng-config-body.in
old mode 100755
new mode 100644
diff --git a/scripts/libpng-config-head.in b/scripts/libpng-config-head.in
old mode 100755
new mode 100644
index 462de74..f3128a4
--- a/scripts/libpng-config-head.in
+++ b/scripts/libpng-config-head.in
@@ -11,7 +11,7 @@
 
 # Modeled after libxml-config.
 
-version=1.6.10
+version=1.6.11
 prefix=""
 libdir=""
 libs=""
diff --git a/scripts/libpng.pc.in b/scripts/libpng.pc.in
index 1ae258b..6ce3f56 100644
--- a/scripts/libpng.pc.in
+++ b/scripts/libpng.pc.in
@@ -5,6 +5,6 @@
 
 Name: libpng
 Description: Loads and saves PNG files
-Version: 1.6.10
+Version: 1.6.11
 Libs: -L${libdir} -lpng16
 Cflags: -I${includedir}
diff --git a/scripts/makefile.amiga b/scripts/makefile.amiga
index 228b5c2..16a4bd5 100644
--- a/scripts/makefile.amiga
+++ b/scripts/makefile.amiga
@@ -24,13 +24,15 @@
 LN= slink
 # file deletion command
 RM= delete quiet
-# file copy command?
-CP= copy
 # library (.lib) file creation command
 AR= oml
 # make directory command
 MKDIR= makedir
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -43,8 +45,8 @@
 
 $(OBJS): pngpriv.h png.h pngconf.h pnglibconf.h pnginfo.h pngstruct.h pngdebug.h
 
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-$(CP) scripts/pnglibconf.h.prebuilt pnglibconf.h
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+COPY $(PNGLIBCONF_H_PREBUILT) TO pnglibconf.h
 
 pngtest: pngtest.o libpng.lib
 $(LN) <WITH <
diff --git a/scripts/makefile.atari b/scripts/makefile.atari
index 051d303..d0aa481 100644
--- a/scripts/makefile.atari
+++ b/scripts/makefile.atari
@@ -29,6 +29,10 @@
 # you execute make install.
 DESTDIR=
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = $(LBR)(png.o) $(LBR)(pngset.o) $(LBR)(pngget.o) $(LBR)(pngrutil.o)\
 	$(LBR)(pngtrans.o) $(LBR)(pngwutil.o)\
 	$(LBR)(pngread.o) $(LBR)(pngerror.o) $(LBR)(pngwrite.o)\
@@ -44,8 +48,8 @@
 
 $(OBJS): pngpriv.h png.h pngconf.h pnglibconf.h pnginfo.h pngstruct.h pngdebug.h
 
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt pnglibconf.h
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	cp $< $@
 
 pngtest.ttp: pngtest.o $(LBR)
 	$(CC) $(CFLAGS) $(LDFLAGS) -o$@ pngtest.o
diff --git a/scripts/makefile.bc32 b/scripts/makefile.bc32
index c2a9122..6fece9c 100644
--- a/scripts/makefile.bc32
+++ b/scripts/makefile.bc32
@@ -11,10 +11,11 @@
 ## Where zlib.h, zconf.h and zlib.lib are
 ZLIB_DIR=..\zlib
 
-## Compiler, linker and lib stuff
+## Compiler, linker, librarian and other tools
 CC=bcc32
 LD=bcc32
 LIB=tlib
+CP=copy
 
 # -3 = 386, -4 = 486, -5 = Pentium etc.
 !ifndef TARGET_CPU
@@ -49,6 +50,10 @@
 # -M  generate map file
 LDFLAGS=-L$(ZLIB_DIR) -M $(LDEBUG)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 ## Variables
 OBJS = \
 	png.obj \
@@ -111,10 +116,8 @@
 
 ## Minor Targets
 
-# see scripts\pnglibconf.mak for how to make this file
-# with different options
-pnglibconf.h: scripts\pnglibconf.h.prebuilt
-	copy scripts\pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 png.obj: png.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
 pngerror.obj: pngerror.c png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
diff --git a/scripts/makefile.beos b/scripts/makefile.beos
index f897d11..edac365 100644
--- a/scripts/makefile.beos
+++ b/scripts/makefile.beos
@@ -24,6 +24,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 
 # Where the zlib library and include files are located
@@ -68,6 +69,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -81,9 +86,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# try include scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.bor b/scripts/makefile.bor
index a032510..254de89 100644
--- a/scripts/makefile.bor
+++ b/scripts/makefile.bor
@@ -12,10 +12,11 @@
 ## Where zlib.h, zconf.h and zlib_MODEL.lib are
 ZLIB_DIR=..\zlib
 
-## Compiler, linker and lib stuff
+## Compiler, linker, librarian and other tools
 CC=bcc
 LD=bcc
 LIB=tlib
+CP=copy
 
 !ifndef MODEL
 MODEL=l
@@ -57,6 +58,10 @@
 # -M  generate map file
 LDFLAGS=-M -L$(ZLIB_DIR) $(MODEL_ARG) $(LDEBUG)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 ## Variables
 
 OBJS = \
@@ -110,9 +115,9 @@
 
 all: libpng pngtest
 
-# try !inlude scripts\pnglibconf.mak for more options
-pnglibconf.h: scripts\pnglibconf.h.prebuilt
-	copy scripts\pnglibconf.h.prebuilt $@
+# try !include scripts\pnglibconf.mak for more options
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng: $(LIBNAME)
 
diff --git a/scripts/makefile.cegcc b/scripts/makefile.cegcc
index e2ff273..efa55df 100644
--- a/scripts/makefile.cegcc
+++ b/scripts/makefile.cegcc
@@ -23,7 +23,7 @@
 
 VERMAJ = 1
 VERMIN = 6
-VERMIC = 10
+VERMIC = 11
 VER = $(VERMAJ).$(VERMIN).$(VERMIC)
 NAME = libpng
 PACKAGE = $(NAME)-$(VER)
diff --git a/scripts/makefile.darwin b/scripts/makefile.darwin
index 7c38c26..fd6adff 100644
--- a/scripts/makefile.darwin
+++ b/scripts/makefile.darwin
@@ -34,6 +34,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 ARCH=-arch ppc -arch i386 -arch x86_64
 
@@ -62,6 +63,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -78,9 +83,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.dec b/scripts/makefile.dec
index 1ba9efb..54cbcac 100644
--- a/scripts/makefile.dec
+++ b/scripts/makefile.dec
@@ -22,6 +22,7 @@
 MKDIR_P=mkdir
 LN_SF=ln -f -s
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 
 # where make install puts libpng.a and png.h
@@ -57,6 +58,10 @@
 CFLAGS=-std -w1 -O # -g
 LDFLAGS=-L$(ZLIBLIB) -rpath $(ZLIBLIB) libpng.a -lz -lm
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -66,9 +71,8 @@
 
 all: $(LIBSO) libpng.a pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@  $(OBJS)
@@ -181,7 +185,7 @@
 	./pngtesti pngtest.png
 
 clean:
-	/bin/rm -f *.o libpng.a pngtest pngtesti pngout.png \
+	$(RM_F) *.o libpng.a pngtest pngtesti pngout.png \
 	libpng-config $(LIBSO) $(LIBSOMAJ)* \
 	libpng.pc pnglibconf.h
 
diff --git a/scripts/makefile.dj2 b/scripts/makefile.dj2
index a43f34a..e21546d 100644
--- a/scripts/makefile.dj2
+++ b/scripts/makefile.dj2
@@ -19,6 +19,13 @@
 
 RANLIB=ranlib
 
+CP=cp
+RM_F=rm -f
+
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o pngwtran.o \
 	pngmem.o pngerror.o pngpread.o
@@ -28,9 +35,8 @@
 
 all: libpng.a pngtest
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	ar rc $@  $(OBJS)
@@ -43,7 +49,7 @@
 test: pngtest
 	./pngtest
 clean:
-	rm -f *.o libpng.a pngtest pngout.png pnglibconf.h
+	$(RM_F) *.o libpng.a pngtest pngout.png pnglibconf.h
 
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
diff --git a/scripts/makefile.elf b/scripts/makefile.elf
index 6da6d4a..e595d95 100644
--- a/scripts/makefile.elf
+++ b/scripts/makefile.elf
@@ -30,6 +30,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 
 # where "make install" puts libpng16.a, libpng16.so*,
@@ -82,6 +83,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -98,9 +103,8 @@
 
 all: libpng.a $(LIBSO) pngtest pngtest-static libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.freebsd b/scripts/makefile.freebsd
index 03a15df..c008435 100644
--- a/scripts/makefile.freebsd
+++ b/scripts/makefile.freebsd
@@ -13,7 +13,7 @@
 SHLIB_MAJOR=	${SHLIB_VER}
 SHLIB_MINOR=	0
 NO_PROFILE=	YES
-NO_OBJ=          YES
+NO_OBJ=		YES
 
 # where make install puts libpng.a and png.h
 DESTDIR=	${PREFIX}
@@ -39,6 +39,10 @@
 CPPFLAGS+=	-I. -I${ZLIBINC}
 CFLAGS+=	-W -Wall
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT= scripts/pnglibconf.h.prebuilt
+
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
@@ -55,9 +59,8 @@
 test: pngtest
 	./pngtest
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	cp $< $@
 
 DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
 writelock:
diff --git a/scripts/makefile.gcc b/scripts/makefile.gcc
index a592294..8811a28 100644
--- a/scripts/makefile.gcc
+++ b/scripts/makefile.gcc
@@ -16,6 +16,7 @@
 LD = $(CC)
 AR_RC = ar rcs
 RANLIB = ranlib
+CP = cp
 RM_F = rm -f
 
 WARNMORE = -Wwrite-strings -Wpointer-arith -Wshadow \
@@ -29,6 +30,10 @@
 # File extensions
 EXEEXT =
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 # Variables
 OBJS =  png.o pngerror.o pngget.o pngmem.o pngpread.o \
 	pngread.o pngrio.o pngrtran.o pngrutil.o pngset.o \
@@ -37,9 +42,8 @@
 # Targets
 all: static
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 .c.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
diff --git a/scripts/makefile.hp64 b/scripts/makefile.hp64
index 6c15a0b..2883d65 100644
--- a/scripts/makefile.hp64
+++ b/scripts/makefile.hp64
@@ -34,6 +34,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 
 CPPFLAGS=-I$(ZLIBINC) \
@@ -67,6 +68,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -83,9 +88,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.hpgcc b/scripts/makefile.hpgcc
index 67d8f42..5c8791b 100644
--- a/scripts/makefile.hpgcc
+++ b/scripts/makefile.hpgcc
@@ -25,6 +25,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 
 # where "make install" puts libpng.a, $(OLDSO)*, png.h, pngconf.h
diff --git a/scripts/makefile.hpux b/scripts/makefile.hpux
index bef2e23..2a4a0b3 100644
--- a/scripts/makefile.hpux
+++ b/scripts/makefile.hpux
@@ -66,6 +66,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -82,9 +86,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.ibmc b/scripts/makefile.ibmc
index 861a551..2f5a03c 100644
--- a/scripts/makefile.ibmc
+++ b/scripts/makefile.ibmc
@@ -21,12 +21,17 @@
 CC = icc
 LD = ilink
 AR = ilib
+CP = copy
 RM = del
 
 CPPFLAGS = -I$(ZLIBINC)
 CFLAGS = -Mc -O2 -W3
 LDFLAGS =
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 # File extensions
 O=.obj
 A=.lib
@@ -45,9 +50,8 @@
 
 all: libpng$(A) pngtest$(E)
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng$(A): $(OBJS)
 	$(AR) -out:$@ $(OBJS)
diff --git a/scripts/makefile.intel b/scripts/makefile.intel
index 1abfc6e..9fa963f 100644
--- a/scripts/makefile.intel
+++ b/scripts/makefile.intel
@@ -36,6 +36,11 @@
 CFLAGS=-O2 -G$(CPU)$(CALLING) -Qip -Qunroll4 -nologo
 LD=link
 LDFLAGS=/SUBSYSTEM:CONSOLE /NOLOGO
+CP=cp
+
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
 
 O=.obj
 
@@ -45,9 +50,8 @@
 
 all: test
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
 	$(CC) $(CPPFLAGS) $(CFLAGS) $*.c $(ERRFILE)
diff --git a/scripts/makefile.knr b/scripts/makefile.knr
index 7209215..38a67cb 100644
--- a/scripts/makefile.knr
+++ b/scripts/makefile.knr
@@ -36,15 +36,21 @@
 RANLIB = ranlib
 #RANLIB = echo
 
+CP = cp
+RM_F = rm -f
+
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
 
 all: ansi2knr libpng.a pngtest
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 # general rule to allow ansi2knr to work
 .c.o:
@@ -83,7 +89,7 @@
 	chmod 644 $(DESTDIR)$(LIBPATH)/libpng.a
 
 clean:
-	rm -f *.o libpng.a pngtest pngout.png ansi2knr pnglibconf.h
+	$(RM_F) *.o libpng.a pngtest pngout.png ansi2knr pnglibconf.h
 
 DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
 writelock:
diff --git a/scripts/makefile.linux b/scripts/makefile.linux
index 73a30c8..9fb3cec 100644
--- a/scripts/makefile.linux
+++ b/scripts/makefile.linux
@@ -10,7 +10,7 @@
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 10
+RELEASE = 11
 
 # Shared library names:
 LIBSO=$(LIBNAME).so
@@ -24,6 +24,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 
 # where "make install" puts libpng16.a, libpng16.so*,
@@ -75,6 +76,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS =  png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -91,9 +96,8 @@
 
 all: libpng.a $(LIBSO) pngtest pngtest-static libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.mips b/scripts/makefile.mips
index a0df001..d171dc4 100644
--- a/scripts/makefile.mips
+++ b/scripts/makefile.mips
@@ -30,6 +30,12 @@
 #RANLIB=ranlib
 RANLIB=echo
 
+CP=cp
+
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -39,9 +45,8 @@
 
 all: libpng.a pngtest
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	ar rc $@  $(OBJS)
diff --git a/scripts/makefile.msc b/scripts/makefile.msc
index 905ed72..6e30e81 100644
--- a/scripts/makefile.msc
+++ b/scripts/makefile.msc
@@ -16,8 +16,13 @@
 CC=cl
 LD=link
 LDFLAGS=/e/st:0x1500/noe
+CP=copy
 O=.obj
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 #uncomment next to put error messages in a file
 ERRFILE= >> pngerrs
 
@@ -28,12 +33,11 @@
 
 all: libpng.lib
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-		  $(CC) -c $(CPPFLAGS) $(CFLAGS) $*.c $(ERRFILE)
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $*.c $(ERRFILE)
 
 pngset$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $*.c $(ERRFILE)
diff --git a/scripts/makefile.msys b/scripts/makefile.msys
index 69fbb4d..28af2b9 100644
--- a/scripts/makefile.msys
+++ b/scripts/makefile.msys
@@ -18,7 +18,7 @@
 # Library name:
 LIBNAME = libpng16
 PNGMAJ = 16
-RELEASE = 10
+RELEASE = 11
 
 # Shared library names:
 LIBSO=$(LIBNAME).dll
@@ -37,6 +37,7 @@
 LD = $(CC)
 AR_RC = ar rcs
 RANLIB = ranlib
+CP = cp
 RM_F = rm -rf
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
@@ -73,6 +74,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 # Variables
 OBJS =  png.o pngerror.o pngget.o pngmem.o pngpread.o \
 	pngread.o pngrio.o pngrtran.o pngrutil.o pngset.o \
@@ -81,9 +86,8 @@
 # Targets
 all: static shared
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 .c.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $<
diff --git a/scripts/makefile.ne12bsd b/scripts/makefile.ne12bsd
index 783e5d5..b62204a 100644
--- a/scripts/makefile.ne12bsd
+++ b/scripts/makefile.ne12bsd
@@ -17,7 +17,7 @@
 
 LIB=	png16
 SHLIB_MAJOR=	0
-SHLIB_MINOR=	1.6.10
+SHLIB_MINOR=	1.6.11
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
@@ -26,6 +26,10 @@
 
 CPPFLAGS+=-I${.CURDIR}
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT= scripts/pnglibconf.h.prebuilt
+
 # We should be able to do something like this instead of the manual
 # uncommenting, but it core dumps for me at the moment:
 # .if ${MACHINE_ARCH} == "i386"
@@ -37,9 +41,8 @@
 .c.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	cp $< $@
 
 pngtest.o:	pngtest.c
 	${CC} -c ${CPPFLAGS} ${CFLAGS} ${.ALLSRC} -o ${.TARGET}
diff --git a/scripts/makefile.netbsd b/scripts/makefile.netbsd
index af4eb93..67b29bc 100644
--- a/scripts/makefile.netbsd
+++ b/scripts/makefile.netbsd
@@ -17,7 +17,7 @@
 
 LIB=	png
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.10
+SHLIB_MINOR=	1.6.11
 SRCS=	png.c pngset.c pngget.c pngrutil.c pngtrans.c pngwutil.c \
 	pngread.c pngrio.c pngwio.c pngwrite.c pngrtran.c \
 	pngwtran.c pngmem.c pngerror.c pngpread.c
@@ -26,6 +26,10 @@
 
 CPPFLAGS+=-I${.CURDIR}
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT= scripts/pnglibconf.h.prebuilt
+
 # We should be able to do something like this instead of the manual
 # uncommenting, but it core dumps for me at the moment:
 # .if ${MACHINE_ARCH} == "i386"
@@ -37,9 +41,8 @@
 .c.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	cp $< $@
 
 pngtest.o:	pngtest.c
 	${CC} -c ${CPPFLAGS} ${CFLAGS} ${.ALLSRC} -o ${.TARGET}
diff --git a/scripts/makefile.openbsd b/scripts/makefile.openbsd
index c61fa2e..ecdc18b 100644
--- a/scripts/makefile.openbsd
+++ b/scripts/makefile.openbsd
@@ -11,7 +11,7 @@
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.10
+SHLIB_MINOR=	1.6.11
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
@@ -31,12 +31,15 @@
 DOCS=	ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO \
 	libpng-manual.txt
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT= scripts/pnglibconf.h.prebuilt
+
 .c.o:
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	cp $< $@
 
 pngtest.o:	pngtest.c
 	${CC} ${CPPFLAGS} ${CFLAGS} -c ${.ALLSRC} -o ${.TARGET}
diff --git a/scripts/makefile.sco b/scripts/makefile.sco
index a8de13f..6e5457d 100644
--- a/scripts/makefile.sco
+++ b/scripts/makefile.sco
@@ -25,6 +25,7 @@
 MKDIR_P=mkdir
 LN_SF=ln -f -s
 RANLIB=echo
+CP=cp
 RM_F=/bin/rm -f
 
 # where make install puts libpng.a, $(OLDSO)*, and png.h
@@ -61,6 +62,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -77,9 +82,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.sggcc b/scripts/makefile.sggcc
index a2c203e..f8721c9 100644
--- a/scripts/makefile.sggcc
+++ b/scripts/makefile.sggcc
@@ -22,6 +22,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=echo
+CP=cp
 RM_F=/bin/rm -f
 
 # Where make install puts libpng.a, libpng16.so, and libpng16/png.h
@@ -71,6 +72,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS =  png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -80,9 +85,8 @@
 
 all: libpng.a pngtest shared libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.sgi b/scripts/makefile.sgi
index 96c61b0..561ce83 100644
--- a/scripts/makefile.sgi
+++ b/scripts/makefile.sgi
@@ -22,6 +22,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -sf
 RANLIB=echo
+CP=cp
 RM_F=/bin/rm -f
 
 # Where make install puts libpng.a, libpng16.so, and libpng16/png.h
@@ -74,6 +75,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS =  png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -83,9 +88,8 @@
 
 all: libpng.a pngtest shared libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.so9 b/scripts/makefile.so9
index 67821f8..9102e69 100644
--- a/scripts/makefile.so9
+++ b/scripts/makefile.so9
@@ -26,6 +26,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -f -s
 RANLIB=echo
+CP=cp
 RM_F=/bin/rm -f
 
 # Where make install puts libpng.a, $(OLDSO)*, and png.h
@@ -71,6 +72,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -87,9 +92,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.solaris b/scripts/makefile.solaris
index 8132199..879e6a4 100644
--- a/scripts/makefile.solaris
+++ b/scripts/makefile.solaris
@@ -24,6 +24,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -f -s
 RANLIB=echo
+CP=cp
 RM_F=/bin/rm -f
 
 # Where make install puts libpng.a, libpng16.so*, and png.h
@@ -67,6 +68,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -83,9 +88,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.solaris-x86 b/scripts/makefile.solaris-x86
index 8d24148..509d5a3 100644
--- a/scripts/makefile.solaris-x86
+++ b/scripts/makefile.solaris-x86
@@ -24,6 +24,7 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -f -s
 RANLIB=echo
+CP=cp
 RM_F=/bin/rm -f
 
 # Where make install puts libpng.a, libpng16.so*, and png.h
@@ -66,6 +67,10 @@
 DL=$(DESTDIR)$(LIBPATH)
 DM=$(DESTDIR)$(MANPATH)
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -82,9 +87,8 @@
 
 all: libpng.a $(LIBSO) pngtest libpng.pc libpng-config
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@ $(OBJS)
diff --git a/scripts/makefile.std b/scripts/makefile.std
index 30a21e2..75bb2de 100644
--- a/scripts/makefile.std
+++ b/scripts/makefile.std
@@ -32,6 +32,7 @@
 MKDIR_P = mkdir
 LN_SF = ln -sf
 RANLIB = ranlib
+CP = cp
 RM_F = rm -f
 AWK = awk
 SED = sed
@@ -44,6 +45,10 @@
 CFLAGS = -O # -g
 LDFLAGS = -L. -L$(ZLIBLIB) -lpng -lz -lm
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
diff --git a/scripts/makefile.sunos b/scripts/makefile.sunos
index bc5f926..df661bf 100644
--- a/scripts/makefile.sunos
+++ b/scripts/makefile.sunos
@@ -37,12 +37,17 @@
 MKDIR_P=mkdir -p
 LN_SF=ln -f -s
 RANLIB=ranlib
+CP=cp
 RM_F=/bin/rm -f
 
 CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
 CFLAGS=-O # $(WARNMORE)
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
 	pngwtran.o pngmem.o pngerror.o pngpread.o
@@ -52,9 +57,8 @@
 
 all: libpng.a pngtest
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 libpng.a: $(OBJS)
 	$(AR_RC) $@  $(OBJS)
diff --git a/scripts/makefile.tc3 b/scripts/makefile.tc3
index 62279b7..e4744a7 100644
--- a/scripts/makefile.tc3
+++ b/scripts/makefile.tc3
@@ -12,6 +12,12 @@
 LD=tcc
 LIB=tlib
 LDFLAGS=-m$(MODEL) -L..\zlib
+CP=copy
+
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 O=.obj
 E=.exe
 
@@ -25,9 +31,8 @@
 
 all: libpng$(MODEL).lib pngtest$(E)
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts/pnglibconf.h.prebuilt
-	cp scripts/pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+	$(CP) $< $@
 
 pngtest: pngtest$(E)
 
diff --git a/scripts/makefile.vcwin32 b/scripts/makefile.vcwin32
index b26c4ac..b17f6a4 100644
--- a/scripts/makefile.vcwin32
+++ b/scripts/makefile.vcwin32
@@ -9,9 +9,9 @@
 # Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib
 # To use, do "nmake /f scripts\makefile.vcwin32"
 
-# -------- Microsoft Visual C++ 2.0 and later, no assembler code --------
+# -------- Microsoft Visual C++ 2.0 and later --------
 
-# Compiler, linker, librarian, and other tools
+# Compiler, linker, librarian and other tools
 CC = cl
 LD = link
 AR = lib
@@ -19,8 +19,13 @@
 CFLAGS  = -nologo -D_CRT_SECURE_NO_DEPRECATE -MD -O2 -W3
 LDFLAGS = -nologo
 ARFLAGS = -nologo
+CP = copy
 RM = del
 
+# Pre-built configuration
+# See scripts/pnglibconf.mak for more options
+PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
+
 # File extensions
 O=.obj
 
@@ -36,9 +41,8 @@
 # Targets
 all: libpng.lib
 
-# see scripts/pnglibconf.mak for more options
-pnglibconf.h: scripts\pnglibconf.h.prebuilt
-       copy scripts\pnglibconf.h.prebuilt $@
+pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
+       $(CP) $< $@
 
 png$(O): png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
 	$(CC) -c $(CPPFLAGS) $(CFLAGS) $*.c $(ERRFILE)
diff --git a/scripts/options.awk b/scripts/options.awk
index 9aff15d..850d90b 100755
--- a/scripts/options.awk
+++ b/scripts/options.awk
@@ -269,7 +269,7 @@
 
          if (val != 1) { # error reading it
             if (val == 0)
-               print "option", opt ": ERROR: missing contination line"
+               print "option", opt ": ERROR: missing continuation line"
             else
                print "option", opt ": ERROR: error reading continuation line"
 
@@ -362,7 +362,7 @@
 
          if (val != 1) { # error reading it
             if (val == 0)
-               print "chunk", opt ": ERROR: missing contination line"
+               print "chunk", opt ": ERROR: missing continuation line"
             else
                print "chunk", opt ": ERROR: error reading continuation line"
 
@@ -493,7 +493,7 @@
    next
 }
 
-# Check for unreognized lines, because of the preprocessing chunk
+# Check for unrecognized lines, because of the preprocessing chunk
 # format errors will be detected on the first pass independent of
 # any other format errors.
 {
@@ -585,7 +585,7 @@
    # If an option[opt] is 'on' then turn on all requires[opt]
    # If an option[opt] is 'off' then turn off all enabledby[opt]
    #
-   # Error out if we have to turn 'on' an 'off' option or vice versa.
+   # Error out if we have to turn 'on' to an 'off' option or vice versa.
    npending = 0
    for (opt in option) if (opt != "") {
       if (option[opt] == "on" || option[opt] == "off") {
@@ -677,7 +677,7 @@
          for (j=1; j<=nreqs; ++j) {
             print "#ifndef PNG_" r[j] "_SUPPORTED" >out
             print "#   undef PNG_on /*!" r[j] "*/" >out
-            # this error appears in the final output if something
+            # This error appears in the final output if something
             # was switched 'on' but the processing above to force
             # the requires did not work
             if (option[i] == "on") {
diff --git a/scripts/pnglibconf.dfa b/scripts/pnglibconf.dfa
old mode 100755
new mode 100644
index 4d4ea8a..294a4e2
--- a/scripts/pnglibconf.dfa
+++ b/scripts/pnglibconf.dfa
@@ -305,10 +305,6 @@
 option FLOATING_POINT
 option FIXED_POINT
 
-# The following is always on (defined empty)
-
-setting CALLOC_SUPPORTED default
-
 # This protects us against compilers that run on a windowing system
 # and thus don't have or would rather us not use the stdio types:
 # stdin, stdout, and stderr.  The only one currently used is stderr
@@ -582,19 +578,21 @@
 # PNG_sRGB_PROFILE_CHECKS setting controls how much work is done during the
 # check:
 #
-# 0: Just validate the profile MD5 signature if present, otherwise use
-#    the checks in option 1.
+# -1: Don't do any sRGB profile checking.
 #
-# 1: Additionally check the length, intent and adler32 checksum of the
-#    actual data.   If enabled this will reject known profiles that have
-#    had the rendering intent in the header changed as well as other edits
-#    done without updating the checksum.  See the discussion below.
+#  0: Just validate the profile MD5 signature if present, otherwise use
+#     the checks in option 1.
 #
-# 2: Additionally checksum all the data using the ethernet CRC32 algorithm.
-#    This makes it more difficult to fake profiles and makes it less likely
-#    to get a false positive on profiles with no signature, but is probably
-#    just a waste of time since all currently approved ICC sRGB profiles have
-#    a secure MD5 signature.
+#  1: Additionally check the length, intent and adler32 checksum of the
+#     actual data.   If enabled this will reject known profiles that have
+#     had the rendering intent in the header changed as well as other edits
+#     done without updating the checksum.  See the discussion below.
+#
+#  2: Additionally checksum all the data using the ethernet CRC32 algorithm.
+#     This makes it more difficult to fake profiles and makes it less likely
+#     to get a false positive on profiles with no signature, but is probably
+#     just a waste of time since all currently approved ICC sRGB profiles have
+#     a secure MD5 signature.
 #
 # The rendering intent.  An ICC profile stores an intended rendering intent,
 # but does not include the value in the signature.  The intent is documented
diff --git a/scripts/pnglibconf.h.prebuilt b/scripts/pnglibconf.h.prebuilt
index 9d4ef5a..304b52a 100644
--- a/scripts/pnglibconf.h.prebuilt
+++ b/scripts/pnglibconf.h.prebuilt
@@ -1,10 +1,10 @@
-/* libpng 1.6.10 STANDARD API DEFINITION */
+/* libpng 1.6.11 STANDARD API DEFINITION */
 
 /* pnglibconf.h - library build configuration */
 
-/* Libpng version 1.6.10 - March 6, 2014 */
+/* Libpng version 1.6.11 - June 5, 2014 */
 
-/* Copyright (c) 1998-2013 Glenn Randers-Pehrson */
+/* Copyright (c) 1998-2014 Glenn Randers-Pehrson */
 
 /* This code is released under the libpng license. */
 /* For conditions of distribution and use, see the disclaimer */
@@ -187,7 +187,6 @@
 /* end of options */
 /* settings */
 #define PNG_API_RULE 0
-#define PNG_CALLOC_SUPPORTED
 #define PNG_COST_SHIFT 3
 #define PNG_DEFAULT_READ_MACROS 1
 #define PNG_GAMMA_THRESHOLD_FIXED 5000
diff --git a/scripts/symbols.def b/scripts/symbols.def
index f509932..29f0a56 100644
--- a/scripts/symbols.def
+++ b/scripts/symbols.def
@@ -1,4 +1,4 @@
-;Version 1.6.10
+;Version 1.6.11
 ;--------------------------------------------------------------
 ; LIBPNG symbol list as a Win32 DEF file
 ; Contains all the symbols that can be exported from libpng
diff --git a/scripts/symbols.dfn b/scripts/symbols.dfn
index 6f52918..0858327 100644
--- a/scripts/symbols.dfn
+++ b/scripts/symbols.dfn
@@ -11,9 +11,9 @@
 
 /* NOTE: making 'symbols.chk' checks both that the exported
  * symbols in the library don't change and (implicitly) that
- * scripts/pnglibconf.h.prebuilt is as expected.  If scripts/pnglibconf.h.prebuilt
- * is remade using scripts/pnglibconf.dfa then this checks the
- * .dfa file too.
+ * scripts/pnglibconf.h.prebuilt is as expected.
+ * If scripts/pnglibconf.h.prebuilt is remade using
+ * scripts/pnglibconf.dfa then this checks the .dfa file too.
  */
 
 #define PNG_EXPORTA(ordinal, type, name, args, attributes)\