diff -burNp fltk-2.0.x-r6970/images/fl_png.cxx fltk-2.0.x-r6970-dud/images/fl_png.cxx
--- fltk-2.0.x-r6970/images/fl_png.cxx	2007-04-16 16:48:06.000000000 +0200
+++ fltk-2.0.x-r6970-dud/images/fl_png.cxx	2010-02-19 22:42:37.719369135 +0100
@@ -62,7 +62,7 @@ bool pngImage::test(const uchar* datas,
 #if !HAVE_LIBPNG
   return 0;
 #else
-  return png_check_sig((png_byte*)datas, (int)size)!=0;
+  return png_sig_cmp((png_byte*)datas, 0, (int)size)!=0;
 #endif
 }