Bug 1706219 - Handle gSavedSate without placements in proton toolbar migration r=Gijs

Depends on D113423

Differential Revision: https://phabricator.services.mozilla.com/D113432

browser/components/customizableui/CustomizableUI.jsm

@@ -641,7 +641,7 @@ var CustomizableUIInternal = {
       return;
     }
 
-    let placements = gSavedState?.placements[CustomizableUI.AREA_NAVBAR];
+    let placements = gSavedState?.placements?.[CustomizableUI.AREA_NAVBAR];
 
     if (!placements) {
       // The profile was created with this version, so no need to migrate.

browser/components/customizableui/test/browser_proton_toolbar_hide_toolbarbuttons.js

@@ -246,9 +246,9 @@ add_task(async function testNullSavedState() {
 });
 
 /**
- * Checks that a saved state that is missing the placements value does not prevent migration.
+ * Checks that a saved state that is missing nav-bar placements does not prevent migration.
  */
-add_task(async function testNullPlacements() {
+add_task(async function testNoNavbarPlacements() {
   await SpecialPowers.pushPrefEnv({
     set: [
       [kPrefProtonToolbarVersion, 0],
@@ -278,3 +278,35 @@ add_task(async function testNullPlacements() {
 
   await SpecialPowers.popPrefEnv();
 });
+
+/**
+ * Checks that a saved state that is missing the placements value does not prevent migration.
+ */
+add_task(async function testNullPlacements() {
+  await SpecialPowers.pushPrefEnv({
+    set: [
+      [kPrefProtonToolbarVersion, 0],
+      [kPrefProtonToolbarEnabled, true],
+    ],
+  });
+
+  let oldState = CustomizableUIBSPass.gSavedState;
+
+  Assert.equal(
+    Services.prefs.getIntPref(kPrefProtonToolbarVersion),
+    0,
+    "Toolbar proton version is 0"
+  );
+
+  let { CustomizableUIInternal } = CustomizableUIBSPass;
+
+  CustomizableUIBSPass.gSavedState = {};
+  CustomizableUIInternal._updateForNewProtonVersion();
+
+  Assert.ok(true, "_updateForNewProtonVersion didn't throw");
+
+  // Cleanup
+  CustomizableUIBSPass.gSavedState = oldState;
+
+  await SpecialPowers.popPrefEnv();
+});