[devel] Relocated png_do_chop() to its original position in pngrtran.c

The change in version 1.2.41beta08 caused transparency to be handled wrong
in some 16-bit datastreams (Yusaku Sugai).

ANNOUNCE

@@ -730,6 +730,9 @@ version 1.4.0beta107 [December 4, 2009]
 
 version 1.4.0beta108 [December 11, 2009]
   Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
+  Relocated png_do_chop() to its original position in pngrtran.c; the
+    change in version 1.2.41beta08 caused transparency to be handled wrong
+    in some 16-bit datastreams (Yusaku Sugai).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -2417,6 +2417,9 @@ version 1.4.0beta107 [December 4, 2009]
 
 version 1.4.0beta108 [December 11, 2009]
   Removed leftover "-DPNG_CONFIGURE_LIBPNG" from contrib/pngminim/*/makefile
+  Relocated png_do_chop() to its original position in pngrtran.c; the
+    change in version 1.2.41beta08 caused transparency to be handled wrong
+    in some 16-bit datastreams (Yusaku Sugai).
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

pngrtran.c

 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.4.0 [December 4, 2009]
+ * Last changed in libpng 1.4.0 [December 11, 2009]
  * Copyright (c) 1998-2009 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.)
@@ -1410,11 +1410,6 @@ png_do_read_transformations(png_structp png_ptr)
       png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1);
 #endif
 
-#ifdef PNG_READ_16_TO_8_SUPPORTED
-   if (png_ptr->transformations & PNG_16_TO_8)
-      png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
-#endif
-
 #ifdef PNG_READ_BACKGROUND_SUPPORTED
    if ((png_ptr->transformations & PNG_BACKGROUND) &&
       ((png_ptr->num_trans != 0 ) ||
@@ -1444,6 +1439,11 @@ png_do_read_transformations(png_structp png_ptr)
           png_ptr->gamma_shift);
 #endif
 
+#ifdef PNG_READ_16_TO_8_SUPPORTED
+   if (png_ptr->transformations & PNG_16_TO_8)
+      png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1);
+#endif
+
 #ifdef PNG_READ_DITHER_SUPPORTED
    if (png_ptr->transformations & PNG_DITHER)
    {