Bug 1785740 - navigating to an about: url should schedule a tab sync. r=teshaq

Differential Revision: https://phabricator.services.mozilla.com/D154956

services/sync/modules/engines/tabs.js

@@ -548,12 +548,9 @@ TabTracker.prototype = {
       return;
     }
 
-    // Synced tabs do not sync certain urls, we should ignore scheduling a sync
-    // if we have navigate to one of those urls
-    if (lazy.TABS_FILTERED_SCHEMES.has(locationURI.scheme)) {
-      return;
-    }
-
+    // We can't filter out tabs that we don't sync here, because we might be
+    // navigating from a tab that we *did* sync to one we do not, and that
+    // tab we *did* sync should no longer be synced.
     this.callScheduleSync();
   },
 

services/sync/tests/unit/test_tab_tracker.js

@@ -297,16 +297,16 @@ add_task(async function run_sync_on_tab_change_test() {
   await tracker.clearChangedIDs();
   clearQuickWriteTimer(tracker);
 
-  _("Test navigating to an about page does not trigger sync");
+  _("Test navigating to an about page does trigger sync");
   tracker.onLocationChange(
     { isTopLevel: true },
     undefined,
     Services.io.newURI("about:config")
   );
-  Assert.ok(!tracker.modified, "about page does not trigger a tab modified");
+  Assert.ok(tracker.modified, "about page does not trigger a tab modified");
   Assert.ok(
-    !tracker.tabsQuickWriteTimer,
-    "about schema should not trigger a sync happening soon"
+    tracker.tabsQuickWriteTimer,
+    "about schema should trigger a sync happening soon"
   );
 
   _("Test adjusting the filterScheme pref works");