Created attachment 141938 [details] [review]
Fix hang when clicking on the user status menu in the overview

shell-global.[ch]: Add shell_global_display_is_grabbed() that
  uses the newly added meta_display_get_grab_op() to check
  for existing grabs.
shell-status-menu.[ch]: Add shell_status_menu_is_active() to
  check if the menu is popped up. Check for active grabs before
  popping the menu up. Use gtk_menu_popdown() rather than
  gtk_widget_hide(). Remove an excess gtk_widget_show() and
  some excess casts.
panel.js: Check whether the status menu is popped up after button
  release, and if it's not popped up, unhighlight the button.

Reported by Nuno Donato

The approach taken here is very correct in terms of determining that we can't pop up the menu and preventing the user from getting stuck. It has some deficiencies:

 - It doesn't provide any hints as to how we would actually make this work
   in the overlay (other than not using a GTK+ menu)

 - Visually disabling the user menu would provide more explanation to the
   user.

But it should be an improvement for now.

Comment on attachment 141938 [details] [review]
Fix hang when clicking on the user status menu in the overview


>+        // This depends on connection ordering: since we are after the Button's
>+        // ::button-release-event handler, calling button.release() will properly
>+        // unset the 'active' flag for this stays-pressed button
>+        statusbutton.button.connect('button-release-event', function (b, e) {
>+            if (!statusmenu.is_active())
>+                statusbutton.release();
>+            return false;
>+        });

I'd add a comment about why we're doing this, to make the button be a no-op when we're holding a grab.
Or maybe just link to this bug.

Pushed (in two parts, forgot to fix up the comment before pushing the first time.)