[libpng16] 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.

ANNOUNCE

 
-Libpng 1.6.10beta02 - February 16, 2014
+Libpng 1.6.10beta02 - February 17, 2014
 
 This is not intended to be a public release.  It will be replaced
 within a few weeks by a public version or by another test version.
@@ -55,7 +55,7 @@ Version 1.6.10beta01 [February 9, 2014]
     and it adds corresponding code to pngimage.c to handle such options
     by not attempting to test them.
 
-Version 1.6.10beta02 [February 16, 2014]
+Version 1.6.10beta02 [February 17, 2014]
   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.
@@ -66,6 +66,10 @@ Version 1.6.10beta02 [February 16, 2014]
     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.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

CHANGES

@@ -4829,7 +4829,7 @@ Version 1.6.10beta01 [February 9, 2014]
     and it adds corresponding code to pngimage.c to handle such options
     by not attempting to test them.
 
-Version 1.6.10beta02 [February 16, 2014]
+Version 1.6.10beta02 [February 17, 2014]
   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.
@@ -4840,6 +4840,10 @@ Version 1.6.10beta02 [February 16, 2014]
     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.
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

pngread.c

@@ -781,11 +781,14 @@ png_read_end(png_structrp png_ptr, png_inforp info_ptr)
       png_uint_32 length = png_read_chunk_header(png_ptr);
       png_uint_32 chunk_name = png_ptr->chunk_name;
 
-      if (chunk_name == png_IHDR)
+      if (chunk_name == png_IEND)
+         png_handle_IEND(png_ptr, info_ptr, length);
+
+      else if (chunk_name == png_IHDR)
          png_handle_IHDR(png_ptr, info_ptr, length);
 
-      else if (chunk_name == png_IEND)
-         png_handle_IEND(png_ptr, info_ptr, length);
+      else if (info_ptr == NULL)
+         png_crc_finish(png_ptr, length);
 
 #ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
       else if ((keep = png_chunk_unknown_handling(png_ptr, chunk_name)) != 0)

pngrutil.c

@@ -1436,7 +1436,7 @@ png_handle_iCCP(png_structrp png_ptr, png_inforp info_ptr, png_uint_32 length)
                               (sizeof local_buffer), &length,
                               profile + (sizeof profile_header), &size, 0);
 
-                           /* Still expect a a buffer error because we expect
+                           /* Still expect a buffer error because we expect
                             * there to be some tag data!
                             */
                            if (size == 0)