[gnome-shell/cherry-pick-50b77390] worldClocks: Ignore locations with unknown timezone

[Iain Lane <iainl src gnome org>]

commit a1af8b94fda59c70fa5ac0b12b956b52d2b15795
Author: Florian Müllner <fmuellner gnome org>
Date:   Sun Apr 28 10:33:41 2019 +0000

    worldClocks: Ignore locations with unknown timezone
    
    We currently assume that every location has an associated timezone.
    While this is sound in the real world, in practise it depends on
    whether or not libgweather can find a corresponding timezone DB
    entry.
    
    This used to be a fringe case, but has become more likely when commit
    https://gitlab.gnome.org/GNOME/libgweather/commit/d7682676ac9 moved
    weather stations from cities to countries - the station itself is un-
    likely to have a timezone entry, and the country may be part of more
    than a single timezone.
    
    It would be good for libgweather to return a timezone for those
    locations again, but we should defend against the case anyway.
    We cannot tell what time it is at a particular location without
    knowing the timezone, so simply filter them out.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/issues/1062
    
    
    (cherry picked from commit 50b77390761192b27305045f7ee4c80e60b9cff0)

 js/ui/dateMenu.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/js/ui/dateMenu.js b/js/ui/dateMenu.js
index fb32fbb2f..06ea2b5a4 100644
--- a/js/ui/dateMenu.js
+++ b/js/ui/dateMenu.js
@@ -118,7 +118,7 @@ var WorldClocksSection = class WorldClocksSection {
             if (!clocks[i].location)
                 continue;
             let l = world.deserialize(clocks[i].location);
-            if (l)
+            if (l && l.get_timezone() != null)
                 this._locations.push({ location: l });
         }