Fix newmail_notifier issue where favicon wasn't changed back to default (#1489313)

CHANGELOG

@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix newmail_notifier issue where favicon wasn't changed back to default (#1489313)
 - Fix setting of Junk and NonJunk flags by markasjunk plugin (#1489285)
 - Fix lack of Reply-To address in header of forwarded message body (#1489298)
 - Fix bugs when invoking contact creation form when read-only addressbook is selected (#1489296)

plugins/newmail_notifier/newmail_notifier.js

@@ -30,9 +30,9 @@ function newmail_notifier_run(prop)
 function newmail_notifier_stop(prop)
 {
     // revert original favicon
-    if (rcmail.env.favicon_href && (!prop || prop.action != 'check-recent')) {
+    if (rcmail.env.favicon_href && rcmail.env.favicon_changed && (!prop || prop.action != 'check-recent')) {
         $('<link rel="shortcut icon" href="'+rcmail.env.favicon_href+'"/>').replaceAll('link[rel="shortcut icon"]');
-        rcmail.env.favicon_href = null;
+        rcmail.env.favicon_changed = 0;
     }
 }
 
@@ -47,7 +47,10 @@ function newmail_notifier_basic()
     var link = $('<link rel="shortcut icon" href="plugins/newmail_notifier/favicon.ico"/>'),
         oldlink = $('link[rel="shortcut icon"]', w.document);
 
-    rcmail.env.favicon_href = oldlink.attr('href');
+    if (!rcmail.env.favicon_href)
+        rcmail.env.favicon_href = oldlink.attr('href');
+
+    rcmail.env.favicon_changed = 1;
     link.replaceAll(oldlink);
 }