[gtk+] widget: Fix propagation of gesture cancellation on widget unrealize/destroy

[Carlos Garnacho <carlosg src gnome org>]

commit 3aaf730901d04a3e4a102cb95e769a48ec5027e3
Author: Carlos Garnacho <carlosg gnome org>
Date:   Wed Sep 16 12:06:46 2015 +0200

    widget: Fix propagation of gesture cancellation on widget unrealize/destroy
    
    At the time event_check_cancel_sequence_on_hierarchy() is called, the widget
    has been already unparented. Given the widget itself is being destroyed,
    cancellation on it is impending in one way or another, we still must
    propagate cancellation across all parents, so retrieve it early before
    possible widget destruction.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754098

 gtk/gtkwidget.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index ebfc1ff..d813e8b 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -7367,8 +7367,7 @@ event_check_cancel_sequence_on_hierarchy (GtkWidget *widget,
   if (source_device &&
       gdk_device_get_source (source_device) != GDK_SOURCE_KEYBOARD &&
       event->type != GDK_ENTER_NOTIFY && event->type != GDK_LEAVE_NOTIFY)
-    cancel_event_sequence_on_hierarchy (widget,
-                                        gtk_get_event_widget (event),
+    cancel_event_sequence_on_hierarchy (NULL, widget,
                                         gdk_event_get_event_sequence (event));
 }
 
@@ -7378,10 +7377,13 @@ _gtk_widget_captured_event (GtkWidget *widget,
 {
   gboolean return_val = FALSE;
   GtkCapturedEventHandler handler;
+  GtkWidget *parent;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), TRUE);
   g_return_val_if_fail (WIDGET_REALIZED_FOR_EVENT (widget, event), TRUE);
 
+  parent = gtk_widget_get_parent (widget);
+
   if (event->type == GDK_EXPOSE)
     {
       g_warning ("Events of type GDK_EXPOSE cannot be synthesized. To get "
@@ -7408,7 +7410,7 @@ _gtk_widget_captured_event (GtkWidget *widget,
       /* We stop event propagation, but still we must ensure the sequence is
        * cancelled across the widget hierarchy.
        */
-      event_check_cancel_sequence_on_hierarchy (widget, event);
+      event_check_cancel_sequence_on_hierarchy (parent, event);
       return_val = TRUE;
     }
 
@@ -7596,6 +7598,7 @@ gtk_widget_event_internal (GtkWidget *widget,
                           GdkEvent  *event)
 {
   gboolean return_val = FALSE, handled;
+  GtkWidget *parent;
 
   /* We check only once for is-still-visible; if someone
    * hides the window in on of the signals on the widget,
@@ -7606,6 +7609,7 @@ gtk_widget_event_internal (GtkWidget *widget,
     return TRUE;
 
   g_object_ref (widget);
+  parent = gtk_widget_get_parent (widget);
 
   if (widget == gtk_get_event_widget (event))
     return_val |= _gtk_widget_run_controllers (widget, event, GTK_PHASE_TARGET);
@@ -7729,7 +7733,7 @@ gtk_widget_event_internal (GtkWidget *widget,
       /* We stop event propagation, but still we must ensure the sequence is
        * cancelled across the widget hierarchy.
        */
-      event_check_cancel_sequence_on_hierarchy (widget, event);
+      event_check_cancel_sequence_on_hierarchy (parent, event);
       return_val = TRUE;
     }