dri/nouveau: fix crash in nouveau_flush

https://bugs.freedesktop.org/show_bug.cgi?id=61947

Note: this is a candidate for the stable branches

diff --git a/src/mesa/drivers/dri/nouveau/nouveau_driver.c b/src/mesa/drivers/dri/nouveau/nouveau_driver.c
index f56b3b2..6c119d5 100644 (file)
--- a/src/mesa/drivers/dri/nouveau/nouveau_driver.c
+++ b/src/mesa/drivers/dri/nouveau/nouveau_driver.c
@@ -69,7 +69,8 @@ nouveau_flush(struct gl_context *ctx)
                __DRIdri2LoaderExtension *dri2 = screen->dri2.loader;
                __DRIdrawable *drawable = nctx->dri_context->driDrawablePriv;
 
-               dri2->flushFrontBuffer(drawable, drawable->loaderPrivate);
+               if (drawable && drawable->loaderPrivate)
+                       dri2->flushFrontBuffer(drawable, drawable->loaderPrivate);
        }
 }