winebus.sys: Support setting SDL controller mapping through environment variable.

dlls/winebus.sys/bus_sdl.c

@@ -1024,8 +1024,15 @@ static DWORD CALLBACK deviceloop_thread(void *args)
     {
         HKEY key;
         static const WCHAR szPath[] = {'m','a','p',0};
+        const char *mapping;
 
-        if (!RegOpenKeyExW(driver_key, szPath, 0, KEY_QUERY_VALUE, &key))
+        if ((mapping = getenv("SDL_GAMECONTROLLERCONFIG")))
+        {
+            TRACE("Setting environment mapping %s\n", debugstr_a(mapping));
+            if (pSDL_GameControllerAddMapping(mapping) < 0)
+                WARN("Failed to add environment mapping %s\n", pSDL_GetError());
+        }
+        else if (!RegOpenKeyExW(driver_key, szPath, 0, KEY_QUERY_VALUE, &key))
         {
             DWORD index = 0;
             CHAR *buffer = NULL;
@@ -1054,8 +1061,9 @@ static DWORD CALLBACK deviceloop_thread(void *args)
 
                 if (rc == STATUS_SUCCESS)
                 {
-                    TRACE("Setting mapping %s...\n",debugstr_an(buffer,29));
-                    pSDL_GameControllerAddMapping(buffer);
+                    TRACE("Setting registry mapping %s\n", debugstr_a(buffer));
+                    if (pSDL_GameControllerAddMapping(buffer) < 0)
+                        WARN("Failed to add registry mapping %s\n", pSDL_GetError());
                     index ++;
                 }
             } while (rc == STATUS_SUCCESS);