http://bugs.gentoo.org/show_bug.cgi?id=308885

--- a/common/gr_texture.c
+++ b/common/gr_texture.c
@@ -419,7 +419,7 @@ read_png_file (GrTexture *texture, char
   if (fread (header, 1, PNG_BYTES_TO_CHECK, file) != PNG_BYTES_TO_CHECK) {
     goto ERROR;
   }
-  if (!png_check_sig (header, PNG_BYTES_TO_CHECK)) {
+  if (png_sig_cmp (header, 0, PNG_BYTES_TO_CHECK)) {
     goto ERROR;
   }