[libpng15] updated configure files
diff --git a/config.h.in b/config.h.in
index 657a003..131e8be 100644
--- a/config.h.in
+++ b/config.h.in
@@ -3,6 +3,9 @@
 /* Define to 1 if you have the <dlfcn.h> header file. */
 #undef HAVE_DLFCN_H
 
+/* Define to 1 if you have the `feenableexcept' function. */
+#undef HAVE_FEENABLEEXCEPT
+
 /* Define to 1 if you have the <inttypes.h> header file. */
 #undef HAVE_INTTYPES_H
 
@@ -88,5 +91,19 @@
 /* Define to empty if `const' does not conform to ANSI C. */
 #undef const
 
+/* Define to the equivalent of the C99 'restrict' keyword, or to
+   nothing if this is not supported.  Do not define if restrict is
+   supported directly.  */
+#undef restrict
+/* Work around a bug in Sun C++: it does not support _Restrict or
+   __restrict__, even though the corresponding Sun C compiler ends up with
+   "#define restrict _Restrict" or "#define restrict __restrict__" in the
+   previous line.  Perhaps some future version of Sun C++ will work with
+   restrict; if so, hopefully it defines __RESTRICT like Sun C does.  */
+#if defined __SUNPRO_CC && !defined __RESTRICT
+# define _Restrict
+# define __restrict__
+#endif
+
 /* Define to `unsigned int' if <sys/types.h> does not define. */
 #undef size_t
diff --git a/configure b/configure
index ab54be7..4a5c4c0 100755
--- a/configure
+++ b/configure
@@ -12269,6 +12269,52 @@
 
 fi
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for C/C++ restrict keyword" >&5
+$as_echo_n "checking for C/C++ restrict keyword... " >&6; }
+if ${ac_cv_c_restrict+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_cv_c_restrict=no
+   # The order here caters to the fact that C++ does not require restrict.
+   for ac_kw in __restrict __restrict__ _Restrict restrict; do
+     cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+typedef int * int_ptr;
+	int foo (int_ptr $ac_kw ip) {
+	return ip[0];
+       }
+int
+main ()
+{
+int s[1];
+	int * $ac_kw t = s;
+	t[0] = 0;
+	return foo(t)
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+  ac_cv_c_restrict=$ac_kw
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+     test "$ac_cv_c_restrict" != no && break
+   done
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_c_restrict" >&5
+$as_echo "$ac_cv_c_restrict" >&6; }
+
+ case $ac_cv_c_restrict in
+   restrict) ;;
+   no) $as_echo "#define restrict /**/" >>confdefs.h
+ ;;
+   *)  cat >>confdefs.h <<_ACEOF
+#define restrict $ac_cv_c_restrict
+_ACEOF
+ ;;
+ esac
+
 
 # Checks for library functions.
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for working strtod" >&5
@@ -12560,6 +12606,65 @@
 fi
 
 
+# The following is for pngvalid, to ensure it catches FP errors even on
+# platforms that don't enable FP exceptions, the function appears in the math
+# library (typically), it's not an error if it is not found.
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for feenableexcept in -lm" >&5
+$as_echo_n "checking for feenableexcept in -lm... " >&6; }
+if ${ac_cv_lib_m_feenableexcept+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lm  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char feenableexcept ();
+int
+main ()
+{
+return feenableexcept ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_m_feenableexcept=yes
+else
+  ac_cv_lib_m_feenableexcept=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_m_feenableexcept" >&5
+$as_echo "$ac_cv_lib_m_feenableexcept" >&6; }
+if test "x$ac_cv_lib_m_feenableexcept" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_LIBM 1
+_ACEOF
+
+  LIBS="-lm $LIBS"
+
+fi
+
+for ac_func in feenableexcept
+do :
+  ac_fn_c_check_func "$LINENO" "feenableexcept" "ac_cv_func_feenableexcept"
+if test "x$ac_cv_func_feenableexcept" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_FEENABLEEXCEPT 1
+_ACEOF
+
+fi
+done
+
 
 LIBPNG_DEFINES=-DPNG_CONFIGURE_LIBPNG
 LIBPNG_DEFINES=$LIBPNG_DEFINES
diff --git a/configure.ac b/configure.ac
index 51f16dc..7526e2e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -76,6 +76,7 @@
 AC_C_CONST
 AC_TYPE_SIZE_T
 AC_STRUCT_TM
+AC_C_RESTRICT
 
 # Checks for library functions.
 AC_FUNC_STRTOD
@@ -90,6 +91,11 @@
     AC_CHECK_LIB(z, ${ZPREFIX}zlibVersion, ,
                  AC_ERROR([zlib not installed])))
 
+# The following is for pngvalid, to ensure it catches FP errors even on
+# platforms that don't enable FP exceptions, the function appears in the math
+# library (typically), it's not an error if it is not found.
+AC_CHECK_LIB([m], [feenableexcept])
+AC_CHECK_FUNCS([feenableexcept])
 
 LIBPNG_DEFINES=-DPNG_CONFIGURE_LIBPNG
 LIBPNG_DEFINES=$LIBPNG_DEFINES