glx: If a destroyed window is bound to the current context, make it not current.

Avoids subsequent crashes due to stale pointers to the DrawableRec, see
https://bugs.freedesktop.org/show_bug.cgi?id=21132#c15 and previous comments.

Signed-off-by: Michel Dänzer <daenzer@vmware.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/glx/glxext.c b/glx/glxext.c
index 93391e9fd..6bc7bef8e 100644
--- a/glx/glxext.c
+++ b/glx/glxext.c
@@ -126,6 +126,10 @@ static Bool DrawableGone(__GLXdrawable *glxPriv, XID xid)
     __GLXcontext *c;
 
     for (c = glxAllContexts; c; c = c->next) {
+        if (c->isCurrent && (c->drawPriv == glxPriv || c->readPriv == glxPriv)) {
+            (*c->loseCurrent)(c);
+            __glXFlushContextCache();
+        }
         if (c->drawPriv == glxPriv)
             c->drawPriv = NULL;
         if (c->readPriv == glxPriv)