ui/gtk: Fix gd_refresh_rate_millihz() when widget window is not realized

gtk_widget_get_window() returns NULL if the widget's window is not realized, and QEMU crashes. Example under gtk 3.22.30 (mate 1.20.1): qemu-system-x86_64: Gdk: gdk_window_get_origin: assertion 'GDK_IS_WINDOW (window)' failed (gdb) bt #0 0x00007ffff496cf70 in gdk_window_get_origin () from /usr/lib64/libgdk-3.so.0 qemu#1 0x00007ffff49582a0 in gdk_display_get_monitor_at_window () from /usr/lib64/libgdk-3.so.0 qemu#2 0x0000555555bb73e2 in gd_refresh_rate_millihz (window=0x5555579d6280) at ui/gtk.c:1973 qemu#3 gd_vc_gfx_init (view_menu=0x5555579f0590, group=0x0, idx=0, con=<optimized out>, vc=0x5555579d4a90, s=0x5555579d49f0) at ui/gtk.c:2048 qemu#4 gd_create_menu_view (s=0x5555579d49f0) at ui/gtk.c:2149 qemu#5 gd_create_menus (s=0x5555579d49f0) at ui/gtk.c:2188 qemu#6 gtk_display_init (ds=<optimized out>, opts=0x55555661ed80 <dpy>) at ui/gtk.c:2256 qemu#7 0x000055555583d5a0 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4358 Fixes: c4c0092 and 28b58f1 (display/gtk: get proper refreshrate) Reported-by: Jan Kiszka <[email protected]> Signed-off-by: Philippe Mathieu-Daudé <[email protected]> Tested-by: Jan Kiszka <[email protected]> Message-id: [email protected] Signed-off-by: Gerd Hoffmann <[email protected]>
borntraeger · Feb 12, 2020 · 7f4d96f · 7f4d96f
1 parent 31ab416
commit 7f4d96f
Showing 1 changed file with 7 additions and 5 deletions.
diff --git a/ui/gtk.c b/ui/gtk.c
@@ -1968,14 +1968,16 @@ static GtkWidget *gd_create_menu_machine(GtkDisplayState *s)
 static int gd_refresh_rate_millihz(GtkWidget *window)
 {
 #ifdef GDK_VERSION_3_22
-    GdkDisplay *dpy = gtk_widget_get_display(window);
     GdkWindow *win = gtk_widget_get_window(window);
-    GdkMonitor *monitor = gdk_display_get_monitor_at_window(dpy, win);
 
-    return gdk_monitor_get_refresh_rate(monitor);
-#else
-    return 0;
+    if (win) {
+        GdkDisplay *dpy = gtk_widget_get_display(window);
+        GdkMonitor *monitor = gdk_display_get_monitor_at_window(dpy, win);
+
+        return gdk_monitor_get_refresh_rate(monitor);
+    }
 #endif
+    return 0;
 }
 
 static GSList *gd_vc_gfx_init(GtkDisplayState *s, VirtualConsole *vc,