From 71fd0e9fa9572aeb56a4fb7f729f69356620d700 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sun, 3 Aug 2008 00:36:52 +0000
Subject: [PATCH] don't keep the transparent palette colour from the previous
 frame for the next one which may not have any transparency at all (#9747)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@54944 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
---
 docs/changes.txt        |  1 +
 src/common/gifdecod.cpp | 13 ++++++-------
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/docs/changes.txt b/docs/changes.txt
index 29320000d9..9f98e8ea1e 100644
--- a/docs/changes.txt
+++ b/docs/changes.txt
@@ -111,6 +111,7 @@ All (GUI):
 - Fixed wrapping bug in wxRichTextCtrl when there were images present;
   now sets the cursor to the next line after pressing Shift+Enter.
 - Fix crash when reading malformed PCX images.
+- Fix bug with wrong transparency in GIF animations (troelsk).
 
 All (Unix):
 
diff --git a/src/common/gifdecod.cpp b/src/common/gifdecod.cpp
index 5437982d7b..30c214aad6 100644
--- a/src/common/gifdecod.cpp
+++ b/src/common/gifdecod.cpp
@@ -186,7 +186,7 @@ bool wxGIFDecoder::ConvertToImage(unsigned int frame, wxImage *image) const
 
 // Get data for current frame
 
-wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const 
+wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const
 {
     return wxSize(GetFrame(frame)->w, GetFrame(frame)->h);
 }
@@ -593,7 +593,7 @@ bool wxGIFDecoder::CanRead(wxInputStream &stream) const
 wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
 {
     unsigned int  global_ncolors = 0;
-    int           bits, interl, transparent, i;
+    int           bits, interl, i;
     wxAnimationDisposal disposal;
     long          size;
     long          delay;
@@ -655,7 +655,7 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
     }
 
     // transparent colour, disposal method and delay default to unused
-    transparent = -1;
+    int transparent = -1;
     disposal = wxANIM_UNSPECIFIED;
     delay = -1;
 
@@ -705,8 +705,7 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
                 delay = 10 * (buf[2] + 256 * buf[3]);
 
                 // read transparent colour index, if used
-                if (buf[1] & 0x01)
-                    transparent = buf[4];
+                transparent = buf[1] & 0x01 ? buf[4] : -1;
 
                 // read disposal method
                 disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
@@ -756,8 +755,8 @@ wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
             pimg->w = buf[4] + 256 * buf[5];
             pimg->h = buf[6] + 256 * buf[7];
 
-            if (anim && ((pimg->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) || 
-			 (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight())))
+            if (anim && ((pimg->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) ||
+                (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight())))
             {
                 Destroy();
                 return wxGIF_INVFORMAT;