From 6905b93447a42e606dfd126b90f75f4cd3c6fe94 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>
Date: Thu, 6 Apr 2017 14:05:11 +0200
Subject: console: add same surface replace pre-condition
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Catch an invalid state early, before a potential use-after-free. This is
mainly useful for documentation purposes.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20170406120513.638-2-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 ui/console.c | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'ui')

diff --git a/ui/console.c b/ui/console.c
index 419b098..0cbe503 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -1538,6 +1538,8 @@ void dpy_gfx_replace_surface(QemuConsole *con,
     DisplaySurface *old_surface = con->surface;
     DisplayChangeListener *dcl;
 
+    assert(old_surface != surface);
+
     con->surface = surface;
     QLIST_FOREACH(dcl, &s->listeners, next) {
         if (con != (dcl->con ? dcl->con : active_console)) {
-- 
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