[virt-tools-list] [virt-viewer] VirtViewerApp: Never remove main window

[Jonathon Jongsma]

On Mon, 2014-11-17 at 18:24 +0100, Christophe Fergeau wrote:
> It's currently possible to destroy any virt-viewer window, including the
> main window. However, some part of the code expects that the main window
> is always present, for example to present status messages.
> 
> In particular, stopping the guest (or running virsh destroy) will close
> all windows: virt_viewer_session_clear_displays will get called, which
> will call into virt_viewer_app_remove_display_removed, and finally into
> virt_viewer_app_remove_nth_window, which will destroy the window being
> removed if it holds the last reference to it.
> 
> So going through virt_viewer_session_clear_displays, all
> VirtViewerWindow instances and their corresponding GtkWindow have been
> destroyed. This is already an issue as VirtViewerApp::main_window will
> be pointing to freed memory.
> 
> When using virt-viewer --reconnect, this will cause a crash when
> restarting the guest in virt_viewer_app_create_session as it tries to
> get a valid GtkWindow through:
> GtkWindow *window = virt_viewer_window_get_window(priv->main_window);
> 
> This commit avoids this issue by special casing the main window in
> virt_viewer_app_remove_nth_window to ensure it never gets removed.
> This is similar to what is done in virt_viewer_app_hide_all_windows.
> ---
>  src/virt-viewer-app.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/src/virt-viewer-app.c b/src/virt-viewer-app.c
> index 88db463..1d0c601 100644
> --- a/src/virt-viewer-app.c
> +++ b/src/virt-viewer-app.c
> @@ -977,8 +977,11 @@ static void virt_viewer_app_remove_nth_window(VirtViewerApp *self,
>      VirtViewerWindow *win = virt_viewer_app_get_nth_window(self, nth);
>      if (!win)
>          return;
> -
>      virt_viewer_window_set_display(win, NULL);
> +    if (win == self->priv->main_window) {
> +        g_debug("Not removing main window %d %p", nth, win);
> +        return;
> +    }
>      virt_viewer_window_hide(win);
>  
>      g_debug("Remove window %d %p", nth, win);

ACK