GtkMenuButton: Avoid direct button access

We were getting ourselves in trouble by casting touch events
to GdkEventButton and poking directly at their internals. Instead,
use GdkEvent API to get what we need.

This fixes a crash when using the gear menu in epiphany with
touch. The same crash also occurred in testmenubutton.

diff --git a/gtk/gtkmenubutton.c b/gtk/gtkmenubutton.c
index 6ea53b2f1d8ec2d7f7769fd1cae50de22f2c2045..80f1c55d6a551e45f84c8daccb494a0c89e7086c 100644 (file)
--- a/gtk/gtkmenubutton.c
+++ b/gtk/gtkmenubutton.c
@@ -372,11 +372,14 @@ menu_position_side_func (GtkMenu       *menu,
 }
 
 static void
-popup_menu (GtkMenuButton  *menu_button,
-            GdkEventButton *event)
+popup_menu (GtkMenuButton *menu_button,
+            GdkEvent      *event)
 {
   GtkMenuButtonPrivate *priv = menu_button->priv;
   GtkMenuPositionFunc func;
+  GdkDevice *device;
+  guint button;
+  guint32 time;
 
   if (priv->func)
     priv->func (priv->user_data);
@@ -395,14 +398,27 @@ popup_menu (GtkMenuButton  *menu_button,
         break;
   }
 
+  if (event)
+    {
+      device = gdk_event_get_device (event);
+      gdk_event_get_button (event, &button);
+      time = gdk_event_get_time (event);
+    }
+  else
+    {
+      device = NULL;
+      button = 0;
+      time = gtk_get_current_event_time ();
+    }
+
   gtk_menu_popup_for_device (GTK_MENU (priv->menu),
-                             event ? event->device : NULL,
+                             device,
                              NULL, NULL,
                              func,
                              GTK_WIDGET (menu_button),
                              NULL,
-                             event ? event->button : 0,
-                             event ? event->time : gtk_get_current_event_time ());
+                             button,
+                             time);
 }
 
 static void
@@ -418,9 +434,7 @@ gtk_menu_button_clicked (GtkButton *button)
 
       event = gtk_get_current_event ();
 
-      popup_menu (menu_button,
-                  (event && event->type != GDK_BUTTON_RELEASE) ?
-                  (GdkEventButton *) event : NULL);
+      popup_menu (menu_button, event);
 
       if (!event ||
           event->type == GDK_KEY_PRESS ||