From 296eb8b54ec28e06976a274e5de86d33c0060a1b Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Sat, 9 Aug 2014 17:14:49 +0100
Subject: [PATCH] fix pngload with libpng >=1.6.11

thaks Lovell
---
 ChangeLog                 |  1 +
 libvips/foreign/vipspng.c | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index 1eb41b48..5d72f281 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -9,6 +9,7 @@
 - vipsthumbnail shrinks to 1/2 window_size: faster and better quality
 - vipsthumbnail defaults to bicubic + nosharpen
 - better rounding behaviour for fixed-point bicubic reduces noise
+- fix pngload with libpng >=1.6.11
 
 4/7/14 started 7.40.4
 - fix vips_rawsave_fd(), thanks aferrero2707 
diff --git a/libvips/foreign/vipspng.c b/libvips/foreign/vipspng.c
index c3a36f56..c8fefc7c 100644
--- a/libvips/foreign/vipspng.c
+++ b/libvips/foreign/vipspng.c
@@ -48,6 +48,8 @@
  * 	  still set color_type to alpha
  * 16/7/13
  * 	- more robust error handling from libpng
+ * 9/8/14
+ * 	- don't check profiles, helps with libpng >=1.6.11
  */
 
 /*
@@ -188,6 +190,13 @@ read_new( VipsImage *out, gboolean readbehind )
 		user_error_function, user_warning_function )) ) 
 		return( NULL );
 
+#ifdef PNG_SKIP_sRGB_CHECK_PROFILE
+	/* Prevent libpng (>=1.6.11) verifying sRGB profiles.
+	 */
+	png_set_option( read->pPng, 
+		PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON );
+#endif /*PNG_SKIP_sRGB_CHECK_PROFILE*/
+
 	/* Catch PNG errors from png_create_info_struct().
 	 */
 	if( setjmp( png_jmpbuf( read->pPng ) ) ) 
@@ -717,6 +726,13 @@ write_new( VipsImage *in )
 		user_error_function, user_warning_function )) ) 
 		return( NULL );
 
+#ifdef PNG_SKIP_sRGB_CHECK_PROFILE
+	/* Prevent libpng (>=1.6.11) verifying sRGB profiles.
+	 */
+	png_set_option( write->pPng, 
+		PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON );
+#endif /*PNG_SKIP_sRGB_CHECK_PROFILE*/
+
 	/* Catch PNG errors from png_create_info_struct().
 	 */
 	if( setjmp( png_jmpbuf( write->pPng ) ) )