From 492e67163e17767bc374f276ee8ca7e3ad3b7b9a Mon Sep 17 00:00:00 2001
From: Glenn Randers-Pehrson <glennrp at users.sourceforge.net>
Date: Sun, 4 Aug 2013 14:03:44 -0500
Subject: [PATCH] [libpng16] Exit loop over tRNS array when a transparent entry
 is

found (performance report by PoChun Chang)
---
 pngrtran.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/pngrtran.c b/pngrtran.c
index e378ceba4..1816ec34e 100644
--- a/pngrtran.c
+++ b/pngrtran.c
@@ -1,7 +1,7 @@
 
 /* pngrtran.c - transforms the data in a row for PNG readers
  *
- * Last changed in libpng 1.6.2 [April 25, 2013]
+ * Last changed in libpng 1.6.4 [(PENDING RELEASE)]
  * Copyright (c) 1998-2013 Glenn Randers-Pehrson
  * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
  * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
@@ -1116,12 +1116,18 @@ png_init_palette_transformations(png_structrp png_ptr)
 
       /* Ignore if all the entries are opaque (unlikely!) */
       for (i=0; i<png_ptr->num_trans; ++i)
+      {
          if (png_ptr->trans_alpha[i] == 255)
             continue;
          else if (png_ptr->trans_alpha[i] == 0)
             input_has_transparency = 1;
          else
+         {
+            input_has_transparency = 1;
             input_has_alpha = 1;
+            break;
+         }
+      }
    }
 
    /* If no alpha we can optimize. */