Bug 1701542 - Use the correct default for the removed recentlyUsedOrder pref. r=mconley

Differential Revision: https://phabricator.services.mozilla.com/D110051

Author: agashlin

browser/components/BrowserGlue.jsm

@@ -3730,11 +3730,12 @@ BrowserGlue.prototype = {
       // Migrate old ctrlTab pref to new ctrlTab pref
       let defaultValue = false;
       let oldPrefName = "browser.ctrlTab.recentlyUsedOrder";
+      let oldPrefDefault = true;
       // Use old pref value if the user used Ctrl+Tab before, elsewise use new default value
       if (Services.prefs.getBoolPref("browser.engagement.ctrlTab.has-used")) {
         let newPrefValue = Services.prefs.getBoolPref(
           oldPrefName,
-          defaultValue
+          oldPrefDefault
         );
         Services.prefs.setBoolPref(
           "browser.ctrlTab.sortByRecentlyUsed",

browser/components/tests/unit/test_browserGlue_migration_ctrltab_recently_used_order.js

@@ -84,6 +84,25 @@ add_task(async function has_used_ctrl_tab_and_its_on() {
   );
 });
 
+add_task(async function has_used_ctrl_tab_and_its_default() {
+  Services.prefs.setIntPref("browser.migration.version", UI_VERSION);
+  Services.prefs.setBoolPref("browser.engagement.ctrlTab.has-used", true);
+  Services.prefs.clearUserPref("browser.ctrlTab.recentlyUsedOrder");
+
+  // Simulate a migration.
+  gBrowserGlue.observe(
+    null,
+    TOPIC_BROWSERGLUE_TEST,
+    TOPICDATA_BROWSERGLUE_TEST
+  );
+
+  // Default had been true
+  Assert.equal(
+    true,
+    Services.prefs.getBoolPref("browser.ctrlTab.sortByRecentlyUsed")
+  );
+});
+
 registerCleanupFunction(() => {
   Services.prefs.clearUserPref("browser.migration.version");
   Services.prefs.clearUserPref("browser.engagement.ctrlTab.has-used");