Bug 1780963 - Fix glodaFacetTabType.openTab when aArgs is given but empty. r=#thunderbird-reviewers,mkmelin

Since bug 1752038, aArgs is an empty object instead of undefined when the global search menu item is used.

Differential Revision: https://phabricator.services.mozilla.com/D154761

--HG--
extra : amend_source : cf5a75b9889415abc1d7be7a88c80c7fb1e22d51

mail/base/content/glodaFacetTab.js

@@ -22,8 +22,8 @@ var glodaFacetTabType = {
     },
   },
   openTab(aTab, aArgs) {
-    // If aArgs is omitted, default to a blank user search.
-    if (!aArgs) {
+    // If aArgs is empty, default to a blank user search.
+    if (!Object.keys(aArgs).length) {
       aArgs = { searcher: new GlodaMsgSearcher(null, "") };
     }
     // we have no browser until our XUL document loads