handle the unlikely case of qglXSwapIntervalSGI becoming invalid after GL restart...

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@11802 d7cf8633-e32d-0410-b094-e92efae38249
::stable-branch::merge=d8dc612f3020e9d9f5f5209e1e6584d9a9a448d8

diff --git a/vid_glx.c b/vid_glx.c
index 9ac4e02fab1e54c66e3c3d22daa71d25df10fa28..5b77483f71c54454c38d7487f045997e018d1a1b 100644 (file)
--- a/vid_glx.c
+++ b/vid_glx.c
@@ -936,7 +936,7 @@ void VID_Finish (void)
                        if (vid_usingvsync != vid_usevsync)
                        {
                                vid_usingvsync = vid_usevsync;
-                               if (qglXSwapIntervalSGI (vid_usevsync))
+                               if (qglXSwapIntervalSGI && qglXSwapIntervalSGI (vid_usevsync))
                                        Con_Print("glXSwapIntervalSGI didn't accept the vid_vsync change, it will take effect on next vid_restart (GLX_SGI_swap_control does not allow turning off vsync)\n");
                        }