From 7f271ba0e317b2eaa3ce1700c7d941f09d3e7bc8 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <slouken@libsdl.org>
Date: Thu, 8 Aug 2013 02:30:32 -0700
Subject: [PATCH] Fixed bug 2009 - Creating texture from 32-bit surface with
 colorkey and per-surface alpha ignores the colorkey

To fix this we need to ignore the alpha channel in the colorkey comparison, which is the way colorkey comparisons are defined in SDL.

We also need to reset the alpha and color modulation when converting a surface.
---
 src/video/SDL_surface.c | 30 +++++++++++++++++++++++++-----
 1 file changed, 25 insertions(+), 5 deletions(-)

diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c
index ea7168865..1d98244bb 100644
--- a/src/video/SDL_surface.c
+++ b/src/video/SDL_surface.c
@@ -255,11 +255,13 @@ SDL_ConvertColorkeyToAlpha(SDL_Surface * surface)
             Uint16 ckey = (Uint16) surface->map->info.colorkey;
             Uint16 mask = (Uint16) (~surface->format->Amask);
 
+            /* Ignore alpha in colorkey comparison */
+            ckey &= mask;
             row = (Uint16 *) surface->pixels;
             for (y = surface->h; y--;) {
                 spot = row;
                 for (x = surface->w; x--;) {
-                    if (*spot == ckey) {
+                    if ((*spot & mask) == ckey) {
                         *spot &= mask;
                     }
                     ++spot;
@@ -277,10 +279,13 @@ SDL_ConvertColorkeyToAlpha(SDL_Surface * surface)
             Uint32 ckey = surface->map->info.colorkey;
             Uint32 mask = ~surface->format->Amask;
 
+            /* Ignore alpha in colorkey comparison */
+            ckey &= mask;
             row = (Uint32 *) surface->pixels;
             for (y = surface->h; y--;) {
                 spot = row;
                 for (x = surface->w; x--;) {
+                    if ((*spot & mask) == ckey) {
                     if (*spot == ckey) {
                         *spot &= mask;
                     }
@@ -802,6 +807,7 @@ SDL_ConvertSurface(SDL_Surface * surface, SDL_PixelFormat * format,
 {
     SDL_Surface *convert;
     Uint32 copy_flags;
+    SDL_Color copy_color;
     SDL_Rect bounds;
 
     /* Check for empty destination palette! (results in empty image) */
@@ -838,7 +844,16 @@ SDL_ConvertSurface(SDL_Surface * surface, SDL_PixelFormat * format,
 
     /* Save the original copy flags */
     copy_flags = surface->map->info.flags;
+    copy_color.r = surface->map->info.r;
+    copy_color.g = surface->map->info.g;
+    copy_color.b = surface->map->info.b;
+    copy_color.a = surface->map->info.a;
+    surface->map->info.r = 0xFF;
+    surface->map->info.g = 0xFF;
+    surface->map->info.b = 0xFF;
+    surface->map->info.a = 0xFF;
     surface->map->info.flags = 0;
+    SDL_InvalidateMap(surface->map);
 
     /* Copy over the image data */
     bounds.x = 0;
@@ -848,16 +863,21 @@ SDL_ConvertSurface(SDL_Surface * surface, SDL_PixelFormat * format,
     SDL_LowerBlit(surface, &bounds, convert, &bounds);
 
     /* Clean up the original surface, and update converted surface */
-    convert->map->info.r = surface->map->info.r;
-    convert->map->info.g = surface->map->info.g;
-    convert->map->info.b = surface->map->info.b;
-    convert->map->info.a = surface->map->info.a;
+    convert->map->info.r = copy_color.r;
+    convert->map->info.g = copy_color.g;
+    convert->map->info.b = copy_color.b;
+    convert->map->info.a = copy_color.a;
     convert->map->info.flags =
         (copy_flags &
          ~(SDL_COPY_COLORKEY | SDL_COPY_BLEND
            | SDL_COPY_RLE_DESIRED | SDL_COPY_RLE_COLORKEY |
            SDL_COPY_RLE_ALPHAKEY));
+    surface->map->info.r = copy_color.r;
+    surface->map->info.g = copy_color.g;
+    surface->map->info.b = copy_color.b;
+    surface->map->info.a = copy_color.a;
     surface->map->info.flags = copy_flags;
+    SDL_InvalidateMap(surface->map);
     if (copy_flags & SDL_COPY_COLORKEY) {
         SDL_bool set_colorkey_by_color = SDL_FALSE;