Fixed bug 5465 - Invalid memcpy inside SDL_GestureDelTouch (Thanks dmikushin and Yuki Okumura)

src/events/SDL_gesture.c

@@ -487,7 +487,9 @@ int SDL_GestureDelTouch(SDL_TouchID touchId)
     SDL_zero(SDL_gestureTouch[i]);
 
     SDL_numGestureTouches--;
-    SDL_memcpy(&SDL_gestureTouch[i], &SDL_gestureTouch[SDL_numGestureTouches], sizeof(SDL_gestureTouch[i]));
+    if (i != SDL_numGestureTouches) {
+        SDL_memcpy(&SDL_gestureTouch[i], &SDL_gestureTouch[SDL_numGestureTouches], sizeof(SDL_gestureTouch[i]));
+    }
     return 0;
 }