Bug 2055614 - SearchEngines.PreventInstalls should suppress OpenSearch add-engine offers instead of blocking discovery. r=Standard8,urlbar-reviewers

Differential Revision: https://phabricator.services.mozilla.com/D313575

Author: mkaply

browser/actors/LinkHandlerChild.sys.mjs

@@ -129,10 +129,6 @@ export class LinkHandlerChild extends JSWindowActorChild {
           }
           break;
         case "search":
-          if (!Services.policies.isAllowed("installSearchEngine")) {
-            break;
-          }
-
           if (!searchAdded && event.type == "DOMLinkAdded") {
             let type = link.type && link.type.toLowerCase();
             type = type.replace(/^\s+|\s*(?:;.*)?$/g, "");

browser/components/enterprisepolicies/tests/browser/browser_policy_search_engine.js

@@ -5,6 +5,8 @@
 ChromeUtils.defineESModuleGetters(this, {
   CustomizableUITestUtils:
     "resource://testing-common/CustomizableUITestUtils.sys.mjs",
+  OpenSearchManager:
+    "moz-src:///browser/components/search/OpenSearchManager.sys.mjs",
   SearchbarTestUtils: "resource://testing-common/UrlbarTestUtils.sys.mjs",
 });
 
@@ -40,6 +42,14 @@ async function test_opensearch(shouldWork) {
       null,
       "There should be no search engines available to add"
     );
+    // The engine is still discovered so it remains usable for a one-off
+    // contextual search; only installing it is prevented.
+    ok(
+      OpenSearchManager.getEngines(tab.linkedBrowser).some(
+        e => e.title == "newEngine"
+      ),
+      "The engine is still discovered for contextual search"
+    );
   }
   popup.hide();
   await BrowserTestUtils.removeTab(tab);

browser/components/search/OpenSearchManager.sys.mjs

@@ -134,7 +134,7 @@ class _OpenSearchManager {
    *   The window whose UI should be updated.
    */
   updateOpenSearchBadge(win) {
-    let engines = this.#offeredEngines.get(win.gBrowser.selectedBrowser);
+    let engines = this.getInstallableEngines(win.gBrowser.selectedBrowser);
     for (let urlbar of /** @type {NodeListOf<UrlbarInput>} */ (
       win.document.querySelectorAll("moz-urlbar")
     )) {
@@ -224,6 +224,24 @@ class _OpenSearchManager {
     return this.#offeredEngines.get(browser) || [];
   }
 
+  /**
+   * Get the open search engines offered by a browser that the user is allowed
+   * to install. Returns an empty list when the installSearchEngine policy
+   * disallows installing engines, even though the engines remain available for
+   * one-off searches (e.g. contextual search).
+   *
+   * @param {MozBrowser} browser
+   *   The browser for which to get the engines.
+   * @returns {OpenSearchData[]}
+   *   The installable open search engines.
+   */
+  getInstallableEngines(browser) {
+    if (!Services.policies.isAllowed("installSearchEngine")) {
+      return [];
+    }
+    return this.getEngines(browser);
+  }
+
   clearEngines(browser) {
     this.#offeredEngines.delete(browser);
     this.#hiddenEngines.delete(browser);

browser/components/search/SearchOneOffs.sys.mjs

@@ -440,7 +440,7 @@ export class SearchOneOffs {
       return;
     }
 
-    const addEngines = lazy.OpenSearchManager.getEngines(
+    const addEngines = lazy.OpenSearchManager.getInstallableEngines(
       this.window.gBrowser.selectedBrowser
     );
 

browser/components/urlbar/content/SearchModeSwitcher.mjs

@@ -619,7 +619,7 @@ export class SearchModeSwitcher {
     this.#buildSettingsButton();
 
     // Add engines that can be installed.
-    let openSearchEngines = lazy.OpenSearchManager.getEngines(
+    let openSearchEngines = lazy.OpenSearchManager.getInstallableEngines(
       browser.selectedBrowser
     );
     openSearchEngines = openSearchEngines.slice(