From 40c304fc065259c07c0f4f7a35efedd205e4f250 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Nicolai=20H=C3=A4hnle?= <nicolai.haehnle@amd.com>
Date: Fri, 27 Jan 2017 11:58:41 +0100
Subject: [PATCH] glx/dri3: handle NULL pointers in loader-to-DRI3 drawable
 conversion
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With a subsequent patch, we might see NULL loaderPrivates, e.g. when
a DRIdrawable is flushed whose corresponding GLXDRIdrawable was destroyed.
This resulted in a crash, since the loader vs. DRI3 drawable structures
have a non-zero offset.

Fixes glx-visuals-{depth,stencil} -pixmap

Cc: 17.0 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
---
 src/glx/dri3_glx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/glx/dri3_glx.c b/src/glx/dri3_glx.c
index 4472a0bed26..f7bcba32f3e 100644
--- a/src/glx/dri3_glx.c
+++ b/src/glx/dri3_glx.c
@@ -81,6 +81,8 @@
 static struct dri3_drawable *
 loader_drawable_to_dri3_drawable(struct loader_dri3_drawable *draw) {
    size_t offset = offsetof(struct dri3_drawable, loader_drawable);
+   if (!draw)
+      return NULL;
    return (struct dri3_drawable *)(((void*) draw) - offset);
 }
 
-- 
2.30.2