[PATCH] desktop-shell: fix the crash while clicking TRANSIENT_INACTIVE window

[Barry Song]

From: Barry Song <barry.song at navico.com>

It is pretty easy to replicate this bug by involving a Qt Window with
Qt::WindowTransparentForInput flag.

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();

    QDialog d1(&w, Qt::WindowTransparentForInput);
    d1.show();

    return a.exec();
}

Click d1 dialog, weston will crash due to NULL==shruf.

Signed-off-by: Barry Song <barry.song at navico.com>
---
 desktop-shell/shell.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index 93b1c70b..9473bac1 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -2697,11 +2697,16 @@ desktop_surface_move(struct weston_desktop_surface *desktop_surface,
 	struct weston_touch *touch = weston_seat_get_touch(seat);
 	struct shell_surface *shsurf =
 		weston_desktop_surface_get_user_data(desktop_surface);
-	struct weston_surface *surface =
-		weston_desktop_surface_get_surface(shsurf->desktop_surface);
-	struct wl_resource *resource = surface->resource;
+	struct weston_surface *surface;
+	struct wl_resource *resource;
 	struct weston_surface *focus;
 
+	if (!shsurf)
+		return;
+
+	surface = weston_desktop_surface_get_surface(shsurf->desktop_surface);
+	resource = surface->resource;
+
 	if (pointer &&
 	    pointer->focus &&
 	    pointer->button_count > 0 &&
-- 
2.17.1