[master] Avoid a possible NULL dereference in debug build,

in png_set_text_2() (bug introduced in libpng-0.95, discovered by Evan Rouault)

ANNOUNCE

 
-Libpng 1.2.39beta02 - July 25, 2009
+Libpng 1.2.39beta02 - July 28, 2009
 
 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.
@@ -46,7 +46,9 @@ Changes since the last public release (1.2.38):
 version 1.2.39beta01 [July 25, 2009]
   Added a prototype for png_64bit_product() in png.c
 
-version 1.2.39beta02 [July 25, 2009]
+version 1.2.39beta02 [July 28, 2009]
+  Avoid a possible NULL dereference in debug build, in png_set_text_2().
+    (bug introduced in libpng-0.95, discovered by Evan Rouault)
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 

CHANGES

@@ -2435,7 +2435,9 @@ version 1.0.47 and 1.2.38 [July 16, 2009]
 version 1.2.39beta01 [July 25, 2009]
   Added a prototype for png_64bit_product() in png.c
 
-version 1.2.39beta02 [July 25, 2009]
+version 1.2.39beta02 [July 28, 2009]
+  Avoid a possible NULL dereference in debug build, in png_set_text_2().
+    (bug introduced in libpng-0.95, discovered by Evan Rouault)
 
 Send comments/corrections/commendations to png-mng-implement at lists.sf.net
 (subscription required; visit

pngrutil.c

 
 /* pngrutil.c - utilities to read a PNG file
  *
- * Last changed in libpng 1.2.38 [July 25, 2009]
+ * Last changed in libpng 1.2.38 [June 16, 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.)

pngset.c

 
 /* pngset.c - storage of image information into info struct
  *
- * Last changed in libpng 1.2.38 [July 16, 2009]
+ * Last changed in libpng 1.2.39 [July 28, 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.)
@@ -708,7 +708,8 @@ png_set_text_2(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr,
 {
    int i;
 
-   png_debug1(1, "in %s storage function", (png_ptr->chunk_name[0] == '\0' ?
+   png_debug1(1, "in %s storage function", ((png_ptr == NULL ||
+      png_ptr->chunk_name[0] == '\0') ?
       "text" : (png_const_charp)png_ptr->chunk_name));
 
    if (png_ptr == NULL || info_ptr == NULL || num_text == 0)