third_party/libpng: update to 1.2.54

third_party/libpng/pngpread.c

 
 /* pngpread.c - read a png file in push mode
  *
  * Last changed in libpng 1.2.44 [June 26, 2010]
  * Copyright (c) 1998-2010 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.)
  *
  * This code is released under the libpng license.
  * For conditions of distribution and use, see the disclaimer
@@ skipping 667 matching lines @@
 
       new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256;
       old_buffer = png_ptr->save_buffer;
       png_ptr->save_buffer = (png_bytep)png_malloc_warn(png_ptr,
          (png_uint_32)new_max);
       if (png_ptr->save_buffer == NULL)
       {
         png_free(png_ptr, old_buffer);
         png_error(png_ptr, "Insufficient memory for save_buffer");
       }
-      png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
-      png_free(png_ptr, old_buffer);
-      png_ptr->save_buffer_max = new_max;
+      else
+      {
+        png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size);
+        png_free(png_ptr, old_buffer);
+        png_ptr->save_buffer_max = new_max;
+      }
    }
    if (png_ptr->current_buffer_size)
    {
       png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size,
          png_ptr->current_buffer_ptr, png_ptr->current_buffer_size);
       png_ptr->save_buffer_size += png_ptr->current_buffer_size;
       png_ptr->current_buffer_size = 0;
    }
    png_ptr->save_buffer_ptr = png_ptr->save_buffer;
    png_ptr->buffer_size = 0;
@@ skipping 531 matching lines @@
 
 png_voidp PNGAPI
 png_get_progressive_ptr(png_structp png_ptr)
 {
    if (png_ptr == NULL)
       return (NULL);
 
    return png_ptr->io_ptr;
 }
 #endif /* PNG_PROGRESSIVE_READ_SUPPORTED */