File libpng14-1.4.4-CVE-2011-2691.patch of Package libpng14.import5847

http://libpng.git.sourceforge.net/git/gitweb.cgi?p=libpng/libpng;a=commit;h=9dad5e37aef295b4ef8dea39392b652deebc9261
--- pngerror.c
+++ pngerror.c
@@ -87,12 +87,17 @@ png_error(png_structp png_ptr, png_const_charp error_message)
 void PNGAPI
 png_err(png_structp png_ptr)
 {
+   /* Prior to 1.4.8 the error_fn received a NULL pointer, expressed
+    * erroneously as '\0', instead of the empty string "".  This was
+    * apparently an error, introduced in libpng-1.2.20, and png_default_error
+    * will crash in this case.
+    */
    if (png_ptr != NULL && png_ptr->error_fn != NULL)
-      (*(png_ptr->error_fn))(png_ptr, '\0');
+      (*(png_ptr->error_fn))(png_ptr, "");
 
    /* If the custom handler doesn't exist, or if it returns,
       use the default handler, which will not return. */
-   png_default_error(png_ptr, '\0');
+   png_default_error(png_ptr, "");
 }
 #endif /* PNG_ERROR_TEXT_SUPPORTED */