[Mesa-stable] [PATCH] dri3: Check for dummyContext to see if the glx_context is valid

[Stefan Dirsch]

According to the comments in src/glx/glxcurrent.c __glXGetCurrentContext()
always returns a valid pointer. If no context is made current, it will
contain dummyContext. Thus a test for NULL will always fail.

https://lists.freedesktop.org/archives/mesa-dev/2016-April/113962.html

Signed-off-by: Stefan Dirsch <sndirsch at suse.de>
Reviewed-by: Egbert Eich <eich at freedesktop.org>
---
 src/glx/dri3_glx.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c
index 6054ffc..e7c2ec1 100644
--- a/src/glx/dri3_glx.c
+++ b/src/glx/dri3_glx.c
@@ -127,13 +127,9 @@ static __DRIcontext *
 glx_dri3_get_dri_context(struct loader_dri3_drawable *draw)
 {
    struct glx_context *gc = __glXGetCurrentContext();
+   struct dri3_context *dri3Ctx = (struct dri3_context *) gc;
 
-   if (gc) {
-      struct dri3_context *dri3Ctx = (struct dri3_context *) gc;
-      return dri3Ctx->driContext;
-   }
-
-   return NULL;
+   return (gc != &dummyContext) ? dri3Ctx->driContext : NULL;
 }
 
 static void
-- 
2.6.2