From 8875e23128affd17a479308c14b7f808b62e0fd4 Mon Sep 17 00:00:00 2001
From: John Cupitt <jcupitt@gmail.com>
Date: Wed, 10 Sep 2014 09:05:13 +0100
Subject: [PATCH] fix a setjmp() loop in pngread

see

https://github.com/jcupitt/libvips/issues/175

stupid setjmp()
---
 libvips/foreign/vipspng.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libvips/foreign/vipspng.c b/libvips/foreign/vipspng.c
index f89bb58d..66f7e396 100644
--- a/libvips/foreign/vipspng.c
+++ b/libvips/foreign/vipspng.c
@@ -509,6 +509,11 @@ png2vips_generate( VipsRegion *or,
 		read->y_pos += 1;
 	}
 
+	/* Turn errors back on. png_read_end() can trigger them too.
+	 */
+	if( setjmp( png_jmpbuf( read->pPng ) ) ) 
+		return( -1 );
+
 	/* We need to shut down the reader immediately at the end of read or
 	 * we won't detach ready for the next image.
 	 */