[master] Reverted png_get_uint_16 macro to beta05 and added a
comment about the potential API incompatibility.
diff --git a/ANNOUNCE b/ANNOUNCE
index 7ebf2ab..a8a3ee2 100644
--- a/ANNOUNCE
+++ b/ANNOUNCE
@@ -71,6 +71,8 @@
compression both fail to declare their input buffers with 'const'.
version 1.4.5beta07 [November 24, 2010]
+ Reverted png_get_uint_16 macro to beta05 and added comment about the
+ potential API incompatibility.
Send comments/corrections/commendations to glennrp at users.sourceforge.net
or to png-mng-implement at lists.sf.net (subscription required; visit
diff --git a/CHANGES b/CHANGES
index 02144ea..f0348c0 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2723,6 +2723,8 @@
compression both fail to declare their input buffers with 'const'.
version 1.4.5beta07 [November 24, 2010]
+ Reverted png_get_uint_16 macro to beta05 and added comment about the
+ potential API incompatibility.
Send comments/corrections/commendations to glennrp at users.sourceforge.net
or to png-mng-implement at lists.sf.net (subscription required; visit
diff --git a/png.h b/png.h
index 79081f3..772f890 100644
--- a/png.h
+++ b/png.h
@@ -2649,17 +2649,21 @@
((png_uint_32)(*((buf) + 1)) << 16) + \
((png_uint_32)(*((buf) + 2)) << 8) + \
((png_uint_32)(*((buf) + 3))))
-# ifdef PNG_READ_INT_FUNCTIONS_SUPPORTED /* Undefined in 1.4.x by default. */
-# define png_get_uint_16(buf) \
- ((png_uint_16) \
- (((unsigned int)(*(buf)) << 8) + \
- ((unsigned int)(*((buf) + 1)))))
-# else
-# define png_get_uint_16(buf) \
- ((png_uint_32) \
- (((unsigned int)(*(buf)) << 8) + \
- ((unsigned int)(*((buf) + 1)))))
-# endif
+
+ /* The following definition introduces an API incompatibility (but not
+ * an ABI incompatibility) with libpng-1.4.0 through 1.4.4. Prior to
+ * libpng-1.4.5 the macro, which is used by default, returned (incorrectly)
+ * a (png_uint_32), while the function, if used instead, correctly returned
+ * a (png_uint_16).
+ *
+ * Libpng versions 1.0.x and 1.2.x only used a function so are not affected
+ * by this potential API incompatibility between macros.
+ */
+# define png_get_uint_16(buf) \
+ ((png_uint_16) \
+ (((unsigned int)(*(buf)) << 8) + \
+ ((unsigned int)(*((buf) + 1)))))
+
# define png_get_int_32(buf) \
((png_int_32)((*(buf) & 0x80) \
? -((png_int_32)((png_get_uint_32(buf) ^ 0xffffffffL) + 1)) \
