gobject: Handle CONSTRUCT_ONLY flag

CONSTRUCT_ONLY properties are supposed to be only writable during
construction, however this is currently only enforced on the C level.

Add some minimal handling for GObjects defined in JS as well, by
redefining the property as read-only when set from the underlying
C code. We know that call happens only during construction, as
g_object_set_property() and friends handle the flag themselves,
and turning the JS property read-only will prevent changes from
javascript (unless it is explicitly made writable again).

1 files changed, 5 insertions, 6 deletions

diff --git a/installed-tests/js/testLegacyGObject.js b/installed-tests/js/testLegacyGObject.js
index f30bc906..c0b6017c 100644
--- a/installed-tests/js/testLegacyGObject.js
+++ b/installed-tests/js/testLegacyGObject.js
@@ -74,12 +74,7 @@ const MyObject = new GObject.Class({
     },
 
     set construct(val) {
-        // this should be called at most once
-        if (this._constructCalled)
-            throw Error('Construct-Only property set more than once');
-
         this._constructProp = val;
-        this._constructCalled = true;
     },
 
     notify_prop() {
@@ -220,13 +215,17 @@ describe('GObject class', function () {
         expect(myInstance3.construct).toEqual('quz');
     });
 
+    it('does not allow changing CONSTRUCT_ONLY properties', function () {
+        myInstance.construct = 'val';
+        expect(myInstance.construct).toEqual('default');
+    });
+
     it('has a name', function () {
         expect(MyObject.name).toEqual('MyObject');
     });
 
     // the following would (should) cause a CRITICAL:
     // myInstance.readonly = 'val';
-    // myInstance.construct = 'val';
 
     it('has a notify signal', function () {
         let notifySpy = jasmine.createSpy('notifySpy');