[PULL,01/13] console: add same surface replace pre-condition

Commit Message

Gerd Hoffmann April 24, 2017, 12:16 p.m. UTC

From: Marc-André Lureau <[e-mail]>

Catch an invalid state early, before a potential use-after-free. This is
mainly useful for documentation purposes.

Signed-off-by: Marc-André Lureau <[e-mail]>
Message-id: [e-mail]
Signed-off-by: Gerd Hoffmann <[e-mail]>
---
 ui/console.c | 2 ++
 1 file changed, 2 insertions(+)

Patch

diff --git a/ui/console.c b/ui/console.c
index 419b098c11..0cbe5033dd 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)) {