[gnome-shell] AppDisplay: fix isTerminal() check for apps without .desktop files

[Jasper St. Pierre <jstpierre src gnome org>]

commit 4ed0f3e5f0f9d2f7d214026c01835eeb818cbc13
Author: Sebastian Keller <sebastian-keller gmx de>
Date:   Sat Jan 18 14:38:41 2014 +0100

    AppDisplay: fix isTerminal() check for apps without .desktop files
    
    If the app has no .desktop file get_app_info() returns null.
    This breaks window switching using the dash for those apps.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=722494

 js/ui/appDisplay.js |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/appDisplay.js b/js/ui/appDisplay.js
index 154ddaa..19ba949 100644
--- a/js/ui/appDisplay.js
+++ b/js/ui/appDisplay.js
@@ -47,7 +47,10 @@ const PAGE_SWITCH_TRESHOLD = 0.2;
 const PAGE_SWITCH_TIME = 0.3;
 
 function _isTerminal(app) {
-    let categories = app.get_app_info().get_categories() || [];
+    let info = app.get_app_info();
+    if (!info)
+        return false;
+    let categories = info.get_categories() || [];
     return categories.indexOf('TerminalEmulator') > -1;
 }