Fix plugin loading on Firefox 153.3 (untrusted URI) (#6058)

As of Firefox 153.3.0esr, Services.scriptloader refuses jar:file: and file:
URIs unless allowUnsafeURL is passed (Mozilla bug 1974213), so no plugin
loads: bootstrap.js fails with "Trying to load untrusted URI", then
"Plugin ... is missing bootstrap method 'startup'".

Pass allowUnsafeURL when loading a plugin's bootstrap.js and prefs.js,
and preference pane scripts, and temporarily enable
security.allow_unsafe_subscript_loads, which covers loads from plugin
code outside the bootstrap scope.

Also add a test that installs a fixture plugin that loads a script from its XPI
and sets a default pref.

---------

Co-authored-by: Dan Stillman <dstillman@zotero.org>

app/assets/prefs.js

@@ -54,6 +54,11 @@ pref("dom.disable_open_during_load", true);
 // scraping the page, since we don't provide any information to the site.
 pref("security.warn_viewing_mixed", false);
 
+// Temporarily allow plugins to load their own scripts from jar:file: URIs with loadSubScript()
+// without passing allowUnsafeURL (Mozilla bug 1974213). This will be disabled once plugins have
+// had time to update.
+pref("security.allow_unsafe_subscript_loads", true);
+
 // We do need synchronous XHR
 pref("network.xhr.block_sync_system_requests", false);
 

chrome/content/zotero/preferences/preferences.js

@@ -317,7 +317,11 @@ var Zotero_Preferences = {
 					sameZoneAs: window,
 				});
 				for (let script of pane.scripts) {
-					Services.scriptloader.loadSubScript(script, pane.scope);
+					// Plugin panes load scripts from jar:file: URIs
+					Services.scriptloader.loadSubScriptWithOptions(script, {
+						target: pane.scope,
+						allowUnsafeURL: true
+					});
 				}
 			}
 			if (pane.stylesheets) {

chrome/content/zotero/xpcom/plugins.js

@@ -206,7 +206,10 @@ Zotero.Plugins = new function () {
 				uri,
 				{
 					target: scope,
-					ignoreCache: true
+					ignoreCache: true,
+					// Plugins are loaded from jar:file: URIs, which the script loader
+					// otherwise refuses (Mozilla bug 1974213)
+					allowUnsafeURL: true
 				}
 			);
 		}
@@ -528,7 +531,8 @@ Zotero.Plugins = new function () {
 				addon.getResourceURI("prefs.js").spec,
 				{
 					target: obj,
-					ignoreCache: true
+					ignoreCache: true,
+					allowUnsafeURL: true
 				}
 			);
 		}
@@ -554,7 +558,8 @@ Zotero.Plugins = new function () {
 				addon.getResourceURI("prefs.js").spec,
 				{
 					target: obj,
-					ignoreCache: true
+					ignoreCache: true,
+					allowUnsafeURL: true
 				}
 			);
 		}

test/tests/data/plugin-loading-test/bootstrap.js

@@ -0,0 +1,14 @@
+/* global Zotero, Services */
+function startup({ rootURI }) {
+	// Load a script from this XPI into the plugin scope
+	Services.scriptloader.loadSubScript(rootURI + 'main.js');
+	Zotero.PluginLoadingTest = pluginLoadingTestMain();
+}
+
+function shutdown() {
+	delete Zotero.PluginLoadingTest;
+}
+
+function install() {}
+
+function uninstall() {}

test/tests/data/plugin-loading-test/main.js

@@ -0,0 +1,3 @@
+function pluginLoadingTestMain() {
+	return 'loaded';
+}

test/tests/data/plugin-loading-test/manifest.json

@@ -0,0 +1,13 @@
+{
+  "manifest_version": 2,
+  "name": "Plugin Loading Test",
+  "version": "1.0",
+  "applications": {
+    "zotero": {
+      "id": "plugin-loading-test@zotero.org",
+      "update_url": "https://www.zotero.org/",
+      "strict_min_version": "7.0",
+      "strict_max_version": "*"
+    }
+  }
+}

test/tests/data/plugin-loading-test/prefs.js

@@ -0,0 +1 @@
+pref("extensions.zotero.pluginLoadingTest.pref", "default");

test/tests/pluginsTest.js

@@ -0,0 +1,29 @@
+describe("Zotero.Plugins", function () {
+	var { AddonManager } = ChromeUtils.importESModule("resource://gre/modules/AddonManager.sys.mjs");
+
+	describe("Loading", function () {
+		var addon;
+
+		afterEach(async function () {
+			if (addon) {
+				await addon.uninstall();
+				addon = null;
+			}
+			Zotero.Prefs.clear('pluginLoadingTest.pref');
+		});
+
+		// The fixture's bootstrap.js loads main.js from its own XPI with
+		// Services.scriptloader.loadSubScript(rootURI + ...), as plugins commonly do
+		it("should load scripts and default prefs from a plugin's XPI", async function () {
+			let dir = getTestDataDirectory();
+			dir.append('plugin-loading-test');
+			let xpiPath = PathUtils.join(await getTempDirectory(), 'plugin-loading-test.xpi');
+			await Zotero.File.zipDirectory(dir.path, xpiPath);
+			addon = await AddonManager.installTemporaryAddon(Zotero.File.pathToFile(xpiPath));
+
+			await waitForCallback(() => Zotero.PluginLoadingTest, 100, 10);
+			assert.equal(Zotero.PluginLoadingTest, 'loaded');
+			assert.equal(Zotero.Prefs.get('pluginLoadingTest.pref'), 'default');
+		});
+	});
+});