pngconf.h.patch

--- src/pngconf.h	2009-02-14 22:59:26.000000000 +0100
+++ src.new/pngconf.h	2013-12-21 13:59:30.898443798 +0100
@@ -311,6 +311,12 @@
 #  define PNG_SETJMP_SUPPORTED
 #endif
 
+
+#if !(defined(PNG_SKIP_SETJMP_CHECK) && PNG_SKIP_SETJMP_CHECK)
+
+/* This is an attempt to get libfreetype 2.5.2 compiled (in sage) with
+ *this* version of libpng */
+
 #ifdef PNG_SETJMP_SUPPORTED
 /* This is an attempt to force a single setjmp behaviour on Linux.  If
  * the X config stuff didn't define _BSD_SOURCE we wouldn't need this.
@@ -343,6 +349,8 @@
 #  endif /* __linux__ */
 #endif /* PNG_SETJMP_SUPPORTED */
 
+#endif /* !(defined(PNG_SKIP_SETJMP_CHECK) && PNG_SKIP_SETJMP_CHECK) */
+
 #ifdef BSD
 #  include <strings.h>
 #else