From 26d2cd70fa35cdfd09fd2f0529482b45c85de800 Mon Sep 17 00:00:00 2001
From: Matthias Clasen <mclasen@redhat.com>
Date: Sun, 10 May 2020 12:50:28 -0400
Subject: [PATCH] widget: Improve automatic component tracking

Print out when components get finalized 'too late', e.g.
in an idle after dispose. This happens sometimes, and
it is useful to differentiate this situation from an
actual, permanent leak.

One example where this shows up is the property action
in examples/exampleapplication9, which keeps a label
alive until the actions are unexported on the bus,
in an idle.
---
 gtk/gtkwidget.c | 34 +++++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 11 deletions(-)

diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index e6c6308ef8..2604a5856b 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -7220,6 +7220,7 @@ typedef struct {
   GType                widget_type;
   GObject             *object;
   gboolean             did_finalize;
+  gboolean             too_late;
 } FinalizeAssertion;
 
 static void
@@ -7228,7 +7229,15 @@ finalize_assertion_weak_ref (gpointer data,
 {
   FinalizeAssertion *assertion = (FinalizeAssertion *)data;
   assertion->did_finalize = TRUE;
+  if (assertion->too_late)
+    {
+      g_critical ("Automated component '%s' of class '%s' finalized after gtk_widget_destroy().\n",
+                  assertion->child_class->name,
+                  g_type_name (assertion->widget_type));
+      g_slice_free (FinalizeAssertion, assertion);
+    }
 }
+
 #endif /* G_ENABLE_CONSISTENCY_CHECKS */
 
 static void
@@ -7304,18 +7313,21 @@ gtk_widget_real_destroy (GtkWidget *object)
 
 #ifdef G_ENABLE_CONSISTENCY_CHECKS
       for (l = assertions; l; l = l->next)
-	{
-	  FinalizeAssertion *assertion = l->data;
+        {
+          FinalizeAssertion *assertion = l->data;
 
-	  if (!assertion->did_finalize)
-	    g_critical ("Automated component '%s' of class '%s' did not finalize in gtk_widget_destroy(). "
-			"Current reference count is %d",
-			assertion->child_class->name,
-			g_type_name (assertion->widget_type),
-			assertion->object->ref_count);
-
-	  g_slice_free (FinalizeAssertion, assertion);
-	}
+          if (!assertion->did_finalize)
+            {
+              g_critical ("Automated component '%s' of class '%s' did not finalize in gtk_widget_destroy(). "
+                          "Current reference count is %d",
+                          assertion->child_class->name,
+                          g_type_name (assertion->widget_type),
+                          assertion->object->ref_count);
+              assertion->too_late = TRUE;
+            }
+          else
+            g_slice_free (FinalizeAssertion, assertion);
+        }
       g_slist_free (assertions);
 #endif /* G_ENABLE_CONSISTENCY_CHECKS */