From 5d1bee0f17351218b24ba0ff1e7267041fc3204e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=B8rgen=20P=2E=20Tjern=C3=B8?=
 <jorgen@valvesoftware.com>
Date: Wed, 7 Aug 2013 16:29:28 -0700
Subject: [PATCH] Ensure that the right window is current in SDL_GL_SwapWindow.

---
 src/video/SDL_video.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/video/SDL_video.c b/src/video/SDL_video.c
index a78104c54..bab6c6cb9 100644
--- a/src/video/SDL_video.c
+++ b/src/video/SDL_video.c
@@ -2854,6 +2854,12 @@ SDL_GL_SwapWindow(SDL_Window * window)
         SDL_SetError("The specified window isn't an OpenGL window");
         return;
     }
+
+    if (SDL_GL_GetCurrentWindow() != window) {
+        SDL_SetError("The specified window has not been made current");
+        return;
+    }
+
     _this->GL_SwapWindow(_this, window);
 }