[gnome-shell] extensionSystem: Always enforce disallowing extensions using sessionMode

[Florian Müllner <fmuellner src gnome org>]

commit 2a9e065cfb896d0405e8011907d41125b4b6b4a7
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Wed Sep 11 20:24:17 2019 +0200

    extensionSystem: Always enforce disallowing extensions using sessionMode
    
    It's currently possible to circumvent the `sessionMode.allowExtensions`
    property: For already enabled extensions one can call reloadExtension
    via DBus, for new extensions it's possible by adding the extension to
    the enabled-extensions gsettings key and setting the
    disable-extension-version-validation key (which triggers a reload of
    `this._enabledExtensions`) and then calling reloadExtension via DBus.
    
    So to enforce `allowExtensions` while still allowing to update
    extensions and keeping the extensionSystem synced with various gsettings
    keys, replace the checks for `this._enabled` with simple checks for
    `Main.sessionMode.allowExtensions` inside `_callExtensionInit()` and
    `_callExtensionEnable()`.
    
    The remaining checks for `this._enabled` are only small optimizations to
    prevent running code on irrelevant sessionMode updates.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/96

 js/ui/extensionSystem.js | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)
---
diff --git a/js/ui/extensionSystem.js b/js/ui/extensionSystem.js
index 99777a6314..d149568101 100644
--- a/js/ui/extensionSystem.js
+++ b/js/ui/extensionSystem.js
@@ -98,6 +98,9 @@ var ExtensionManager = class {
     }
 
     _callExtensionEnable(uuid) {
+        if (!Main.sessionMode.allowExtensions)
+            return;
+
         let extension = this.lookup(uuid);
         if (!extension)
             return;
@@ -302,6 +305,9 @@ var ExtensionManager = class {
     }
 
     _callExtensionInit(uuid) {
+        if (!Main.sessionMode.allowExtensions)
+            return;
+
         let extension = this.lookup(uuid);
         if (!extension)
             throw new Error("Extension was not properly created. Call createExtensionObject first");
@@ -385,9 +391,6 @@ var ExtensionManager = class {
     _onEnabledExtensionsChanged() {
         let newEnabledExtensions = this._getEnabledExtensions();
 
-        if (!this._enabled)
-            return;
-
         // Find and enable all the newly enabled extensions: UUIDs found in the
         // new setting, but not in the old one.
         newEnabledExtensions.filter(
@@ -426,11 +429,9 @@ var ExtensionManager = class {
             this.reloadExtension(extension);
         this._enabledExtensions = this._getEnabledExtensions();
 
-        if (Main.sessionMode.allowExtensions) {
-            this._enabledExtensions.forEach(uuid => {
-                this._callExtensionEnable(uuid);
-            });
-        }
+        this._enabledExtensions.forEach(uuid => {
+            this._callExtensionEnable(uuid);
+        });
     }
 
     _loadExtensions() {