[gtk+] gtkwidget: Ensure unrealization during event dispatching cancels gestures

[Carlos Garnacho <carlosg src gnome org>]

commit 13873d2c507783042df55ad2c48f37a346121fd0
Author: Carlos Garnacho <carlosg gnome org>
Date:   Thu Sep 10 14:18:04 2015 +0200

    gtkwidget: Ensure unrealization during event dispatching cancels gestures
    
    We use to rely on grab broken events for most of the event sequence
    lifetime, this breaks though on GDK_BUTTON_RELEASE/GDK_TOUCH_END, as there's
    no longer a grab at that time.
    
    For these cases (and all others where there's destroy/unrealize calls
    involved during event dispatching), catch this on the late
    WIDGET_REALIZED_FOR_EVENT calls on widget event handling functions.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754098

 gtk/gtkwidget.c |   34 ++++++++++++++++++++++++++++++++--
 1 files changed, 32 insertions(+), 2 deletions(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 0eda0e2..17cd274 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -7357,6 +7357,22 @@ cancel_event_sequence_on_hierarchy (GtkWidget        *widget,
     }
 }
 
+static void
+event_check_cancel_sequence_on_hierarchy (GtkWidget *widget,
+                                          GdkEvent  *event)
+{
+  GdkDevice *source_device;
+
+  source_device = gdk_event_get_source_device (event);
+
+  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),
+                                        gdk_event_get_event_sequence (event));
+}
+
 gboolean
 _gtk_widget_captured_event (GtkWidget *widget,
                             GdkEvent  *event)
@@ -7387,7 +7403,15 @@ _gtk_widget_captured_event (GtkWidget *widget,
   g_object_ref (widget);
 
   return_val |= handler (widget, event);
-  return_val |= !WIDGET_REALIZED_FOR_EVENT (widget, event);
+
+  if (!WIDGET_REALIZED_FOR_EVENT (widget, event))
+    {
+      /* 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);
+      return_val = TRUE;
+    }
 
   /* The widget that was originally to receive the event
    * handles motion hints, but the capturing widget might
@@ -7702,7 +7726,13 @@ gtk_widget_event_internal (GtkWidget *widget,
   if (WIDGET_REALIZED_FOR_EVENT (widget, event))
     g_signal_emit (widget, widget_signals[EVENT_AFTER], 0, event);
   else
-    return_val = TRUE;
+    {
+      /* 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);
+      return_val = TRUE;
+    }
 
   g_object_unref (widget);