[gnome-shell] shell-window-tracker: Detect invalid PID values of 0

[Florian Müllner <fmuellner src gnome org>]

commit 4aee87a31b1f73ef6f5a7f3928e54d336bc37f02
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Mon Apr 6 20:28:00 2020 +0200

    shell-window-tracker: Detect invalid PID values of 0
    
    MetaWindows get_pid() API changed to use the client PID, which also
    works for Wayland clients instead of only X11 clients now. This API
    returns 0 instead of -1 for invalid PIDs, so update our check according
    to that.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1184

 src/shell-window-tracker.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/shell-window-tracker.c b/src/shell-window-tracker.c
index 075cb2a164..99ed8270c0 100644
--- a/src/shell-window-tracker.c
+++ b/src/shell-window-tracker.c
@@ -343,7 +343,7 @@ get_app_from_window_pid (ShellWindowTracker  *tracker,
 
   pid = meta_window_get_pid (window);
 
-  if (pid == -1)
+  if (pid < 1)
     return NULL;
 
   result = shell_window_tracker_get_app_from_pid (tracker, pid);