Fixed bug 4264 - SDL_CreateTextureFromSurface generates error message but returns ok

Anthony @ POW Games

SDL_CreateTextureFromSurface makes an internal call to SDL_GetColorKey which can return an error and spams the error log with "Surface doesn't have a colorkey" even though the original function didn't return an error.

include/SDL_surface.h

@@ -248,6 +248,13 @@ extern DECLSPEC int SDLCALL SDL_SetSurfaceRLE(SDL_Surface * surface,
 extern DECLSPEC int SDLCALL SDL_SetColorKey(SDL_Surface * surface,
                                             int flag, Uint32 key);
 
+/**
+ *  \brief Returns whether the surface has a color key
+ *
+ *  \return SDL_TRUE if the surface has a color key, or SDL_FALSE if the surface is NULL or has no color key
+ */
+extern DECLSPEC SDL_bool SDLCALL SDL_HasColorKey(SDL_Surface * surface);
+
 /**
  *  \brief Gets the color key (transparent pixel) in a blittable surface.
  *

src/dynapi/SDL_dynapi_overrides.h

@@ -696,3 +696,4 @@
 #define SDL_SensorUpdate SDL_SensorUpdate_REAL
 #define SDL_IsTablet SDL_IsTablet_REAL
 #define SDL_GetDisplayOrientation SDL_GetDisplayOrientation_REAL
+#define SDL_HasColorKey SDL_HasColorKey_REAL

src/dynapi/SDL_dynapi_procs.h

@@ -738,3 +738,4 @@ SDL_DYNAPI_PROC(void,SDL_SensorClose,(SDL_Sensor *a),(a),)
 SDL_DYNAPI_PROC(void,SDL_SensorUpdate,(void),(),)
 SDL_DYNAPI_PROC(SDL_bool,SDL_IsTablet,(void),(),return)
 SDL_DYNAPI_PROC(SDL_DisplayOrientation,SDL_GetDisplayOrientation,(int a),(a),return)
+SDL_DYNAPI_PROC(SDL_bool,SDL_HasColorKey,(SDL_Surface *a),(a),return)

src/render/SDL_render.c

@@ -649,7 +649,7 @@ SDL_CreateTextureFromSurface(SDL_Renderer * renderer, SDL_Surface * surface)
 
     /* See what the best texture format is */
     fmt = surface->format;
-    if (fmt->Amask || SDL_GetColorKey(surface, NULL) == 0) {
+    if (fmt->Amask || (SDL_HasColorKey(surface) && SDL_GetColorKey(surface, NULL) == 0)) {
         needAlpha = SDL_TRUE;
     } else {
         needAlpha = SDL_FALSE;

src/video/SDL_surface.c

@@ -292,6 +292,20 @@ SDL_SetColorKey(SDL_Surface * surface, int flag, Uint32 key)
     return 0;
 }
 
+SDL_bool
+SDL_HasColorKey(SDL_Surface * surface)
+{
+    if (!surface) {
+        return SDL_FALSE;
+    }
+
+    if (!(surface->map->info.flags & SDL_COPY_COLORKEY)) {
+        return SDL_FALSE;
+    }
+
+	return SDL_TRUE;
+}
+
 int
 SDL_GetColorKey(SDL_Surface * surface, Uint32 * key)
 {