Bug 1551213 - Update commands on show in HTML about:addons r=mixedpuppy,kmag

Differential Revision: https://phabricator.services.mozilla.com/D33304

--HG--
extra : moz-landing-system : lando

toolkit/mozapps/extensions/content/extensions.js

@@ -3842,6 +3842,7 @@ function htmlView(type) {
     async show(param, request, state, refresh) {
       await htmlBrowserLoaded;
       await this.node.contentWindow.show(type, param);
+      gViewController.updateCommands();
       gViewController.notifyViewChanged();
     },
 

toolkit/mozapps/extensions/test/browser/browser_html_detail_view.js

@@ -824,3 +824,42 @@ add_task(async function testPermissions() {
   info("Check permissions for add-on without permission messages");
   await runTest("addon2@mochi.test");
 });
+
+// When the back button is used, its disabled state will be updated. If it
+// isn't updated when showing a view, then it will be disabled on the next
+// use (bug 1551213) if the last use caused it to become disabled.
+add_task(async function testGoBackButton() {
+  // Make sure the list view is the first loaded view so you cannot go back.
+  Services.prefs.setCharPref(PREF_UI_LASTCATEGORY, "addons://list/extension");
+
+  let id = "addon1@mochi.test";
+  let win = await loadInitialView("extension");
+  let doc = win.document;
+  let backButton = win.managerWindow.document.getElementById("go-back");
+
+  let loadDetailView = () => {
+    let loaded = waitForViewLoad(win);
+    getAddonCard(doc, id).querySelector("[action=expand]").click();
+    return loaded;
+  };
+
+  let checkBackButtonState = () => {
+    is_element_visible(backButton, "Back button is visible on the detail page");
+    ok(!backButton.disabled, "Back button is enabled");
+  };
+
+  // Load the detail view, first time should be fine.
+  await loadDetailView();
+  checkBackButtonState();
+
+  // Use the back button directly to pop from history and trigger its disabled
+  // state to be updated.
+  let loaded = waitForViewLoad(win);
+  backButton.click();
+  await loaded;
+
+  await loadDetailView();
+  checkBackButtonState();
+
+  await closeView(win);
+});