[gjs: 6/12] GObject: Guard against classes with GType name 'Gjs_'

[Philip Chimento <pchimento src gnome org>]

commit 276ef4153b73d54b5ed1d9a2ece921a6f71147b3
Author: Philip Chimento <philip chimento gmail com>
Date:   Thu Feb 18 18:39:02 2021 -0800

    GObject: Guard against classes with GType name 'Gjs_'
    
    Previously, if an anonymous class expression was passed to
    GObject.registerClass(), then the GType name would become 'Gjs_', meaning
    that only one of these classes could ever be registered in the same
    process.
    
    Instead, use a name based on a UUID when the class expression is
    anonymous. I chose a UUID, and not a sequence number, for example, so that
    it is random and cannot be the same in any two given runs.

 installed-tests/js/testGObjectClass.js | 11 +++++++++++
 modules/core/overrides/GObject.js      |  5 ++++-
 2 files changed, 15 insertions(+), 1 deletion(-)
---
diff --git a/installed-tests/js/testGObjectClass.js b/installed-tests/js/testGObjectClass.js
index dd0f2dca..4cf3a867 100644
--- a/installed-tests/js/testGObjectClass.js
+++ b/installed-tests/js/testGObjectClass.js
@@ -153,6 +153,8 @@ const MyCustomInit = GObject.registerClass(class MyCustomInit extends GObject.Ob
     }
 });
 
+const NoName = GObject.registerClass(class extends GObject.Object {});
+
 describe('GObject class with decorator', function () {
     let myInstance;
     beforeEach(function () {
@@ -337,6 +339,15 @@ describe('GObject class with decorator', function () {
         expect(obj instanceof MyObject).toBeTruthy();
     });
 
+    it('handles anonymous class expressions', function () {
+        const obj = new NoName();
+        expect(obj instanceof NoName).toBeTruthy();
+
+        const NoName2 = GObject.registerClass(class extends GObject.Object {});
+        const obj2 = new NoName2();
+        expect(obj2 instanceof NoName2).toBeTruthy();
+    });
+
     it('calls its _instance_init() function while chaining up in constructor', function () {
         let instance = new MyCustomInit();
         expect(instance.foo).toBeTruthy();
diff --git a/modules/core/overrides/GObject.js b/modules/core/overrides/GObject.js
index 640a4fc6..8058a2ec 100644
--- a/modules/core/overrides/GObject.js
+++ b/modules/core/overrides/GObject.js
@@ -4,7 +4,7 @@
 // SPDX-FileCopyrightText: 2017 Philip Chimento <philip chimento gmail com>, <philip endlessm com>
 
 const Gi = imports._gi;
-const GjsPrivate = imports.gi.GjsPrivate;
+const {GjsPrivate, GLib} = imports.gi;
 const {_checkAccessors} = imports._common;
 const Legacy = imports._legacy;
 
@@ -151,6 +151,9 @@ function _createGTypeName(klass) {
             gtypeClassName = `${callerBasename}_${gtypeClassName}`;
     }
 
+    if (gtypeClassName === '')
+        gtypeClassName = `anonymous_${GLib.uuid_string_random()}`;
+
     return sanitizeGType(`Gjs_${gtypeClassName}`);
 }