gtype: disallow adding interfaces after the fact

Add a check to prevent adding an interface to a class that has already
had its class_init done.

This is an incompatible change but it is suspected that there are not
many users of this functionality.  Two known exceptions are pygobject
(fixed in bug 686149) and our own testsuite (affected tests have been
temporarily disabled by this patch).

Once we confirm that nobody else is using this functionality we can
remove a rather large amount of code for dealing with this case.

https://bugzilla.gnome.org/show_bug.cgi?id=687659

3 files changed, 18 insertions, 11 deletions

diff --git a/gobject/gtype.c b/gobject/gtype.c
index 0fae5c849..6df810c14 100644
--- a/gobject/gtype.c
+++ b/gobject/gtype.c
@@ -1002,6 +1002,12 @@ check_add_interface_L (GType instance_type,
 		 NODE_NAME (node));
       return FALSE;
     }
+  if (node->data && node->data->class.class)
+    {
+      g_warning ("attempting to add an interface (%s) to class (%s) after class_init",
+                 NODE_NAME (iface), NODE_NAME (node));
+      return FALSE;
+    }
   tnode = lookup_type_node_I (NODE_PARENT_TYPE (iface));
   if (NODE_PARENT_TYPE (tnode) && !type_lookup_iface_entry_L (node, tnode))
     {
diff --git a/gobject/tests/threadtests.c b/gobject/tests/threadtests.c
index fd3322207..37b6b70e5 100644
--- a/gobject/tests/threadtests.c
+++ b/gobject/tests/threadtests.c
@@ -25,6 +25,8 @@
 
 static volatile int mtsafe_call_counter = 0; /* multi thread safe call counter */
 static int          unsafe_call_counter = 0; /* single-threaded call counter */
+static GCond sync_cond;
+static GMutex sync_mutex;
 
 #define NUM_COUNTER_INCREMENTS 100000
 
@@ -52,10 +54,6 @@ typedef GTypeInterface MyFace1Interface;
 static GType my_face1_get_type (void);
 G_DEFINE_INTERFACE (MyFace1, my_face1, G_TYPE_OBJECT);
 static void my_face1_default_init (MyFace1Interface *iface) { call_counter_init (iface); }
-typedef GTypeInterface MyFace2Interface;
-static GType my_face2_get_type (void);
-G_DEFINE_INTERFACE (MyFace2, my_face2, G_TYPE_OBJECT);
-static void my_face2_default_init (MyFace2Interface *iface) { call_counter_init (iface); }
 
 /* define 3 test objects, adding interfaces 0 & 1, and adding interface 2 after class initialization */
 typedef GObject         MyTester0;
@@ -69,6 +67,14 @@ static void my_tester0_init (MyTester0*t) {}
 static void my_tester0_class_init (MyTester0Class*c) { call_counter_init (c); }
 typedef GObject         MyTester1;
 typedef GObjectClass    MyTester1Class;
+
+/* Disabled for now (see https://bugzilla.gnome.org/show_bug.cgi?id=687659) */
+#if 0
+typedef GTypeInterface MyFace2Interface;
+static GType my_face2_get_type (void);
+G_DEFINE_INTERFACE (MyFace2, my_face2, G_TYPE_OBJECT);
+static void my_face2_default_init (MyFace2Interface *iface) { call_counter_init (iface); }
+
 static GType my_tester1_get_type (void);
 G_DEFINE_TYPE_WITH_CODE (MyTester1, my_tester1, G_TYPE_OBJECT,
                          G_IMPLEMENT_INTERFACE (my_face0_get_type(), interface_per_class_init);
@@ -86,9 +92,6 @@ G_DEFINE_TYPE_WITH_CODE (MyTester2, my_tester2, G_TYPE_OBJECT,
 static void my_tester2_init (MyTester2*t) {}
 static void my_tester2_class_init (MyTester2Class*c) { call_counter_init (c); }
 
-static GCond sync_cond;
-static GMutex sync_mutex;
-
 static gpointer
 tester_init_thread (gpointer data)
 {
@@ -140,6 +143,7 @@ test_threaded_class_init (void)
   /* ensure non-corrupted counter updates */
   g_assert_cmpint (g_atomic_int_get (&mtsafe_call_counter), ==, unsafe_call_counter);
 }
+#endif
 
 typedef struct {
   GObject parent;
@@ -337,7 +341,7 @@ main (int   argc,
 {
   g_test_init (&argc, &argv, NULL);
 
-  g_test_add_func ("/GObject/threaded-class-init", test_threaded_class_init);
+  /* g_test_add_func ("/GObject/threaded-class-init", test_threaded_class_init); */
   g_test_add_func ("/GObject/threaded-object-init", test_threaded_object_init);
   g_test_add_func ("/GObject/threaded-weak-ref", test_threaded_weak_ref);
 
diff --git a/tests/gobject/Makefile.am b/tests/gobject/Makefile.am
index 63f2bcfd3..9679e050b 100644
--- a/tests/gobject/Makefile.am
+++ b/tests/gobject/Makefile.am
@@ -59,9 +59,6 @@ test_programs =					\
 	accumulator				\
 	defaultiface				\
 	dynamictype				\
-	ifacecheck				\
-	ifaceinit				\
-	ifaceinherit				\
 	override				\
 	performance				\
 	performance-threaded			\