[mutter/gnome-3-22] wayland/xdg-popup: Always use monitor of toplevel

[Jonas Ådahl <jadahl src gnome org>]

commit c042c835a51ce73ba5a41d8205aac98d96c21bf2
Author: Jonas Ådahl <jadahl gmail com>
Date:   Fri Sep 23 17:15:56 2016 +0800

    wayland/xdg-popup: Always use monitor of toplevel
    
    Always use the monitor of the toplevel surface's window, so that the
    popup menu and the parent will always have the same scale. This fixes
    the dimensions sent in the xdg_popup configure event.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=771841

 src/wayland/meta-wayland-xdg-shell.c |    1 +
 src/wayland/meta-window-wayland.c    |   24 ++++++++++++++++++------
 2 files changed, 19 insertions(+), 6 deletions(-)
---
diff --git a/src/wayland/meta-wayland-xdg-shell.c b/src/wayland/meta-wayland-xdg-shell.c
index e9223a9..591a1ed 100644
--- a/src/wayland/meta-wayland-xdg-shell.c
+++ b/src/wayland/meta-wayland-xdg-shell.c
@@ -1463,6 +1463,7 @@ xdg_surface_constructor_get_toplevel (struct wl_client   *client,
 
   window = meta_window_wayland_new (meta_get_display (), surface);
   meta_wayland_surface_set_window (surface, window);
+  meta_window_update_monitor (window, FALSE);
 }
 
 static void
diff --git a/src/wayland/meta-window-wayland.c b/src/wayland/meta-window-wayland.c
index 1b3e090..fd630ca 100644
--- a/src/wayland/meta-window-wayland.c
+++ b/src/wayland/meta-window-wayland.c
@@ -334,19 +334,31 @@ scale_rect_size (MetaRectangle *rect,
 static void
 meta_window_wayland_update_main_monitor (MetaWindow *window)
 {
+  MetaWindow *toplevel_window;
   const MetaMonitorInfo *from;
   const MetaMonitorInfo *to;
   const MetaMonitorInfo *scaled_new;
   float scale;
   MetaRectangle rect;
 
-  /* Require both the current and the new monitor would be the new main monitor,
-   * even given the resulting scale the window would end up having. This is
-   * needed to avoid jumping back and forth between the new and the old, since
-   * changing main monitor may cause the window to be resized so that it no
-   * longer have that same new main monitor. */
   from = window->monitor;
-  to = meta_screen_calculate_monitor_for_window (window->screen, window);
+
+  /* If the window is not a toplevel window (i.e. it's a popup window) just use
+   * the monitor of the toplevel. */
+  toplevel_window = meta_wayland_surface_get_toplevel_window (window->surface);
+  if (toplevel_window != window)
+    {
+      to = toplevel_window->monitor;
+    }
+  else
+    {
+      /* Require both the current and the new monitor would be the new main monitor,
+       * even given the resulting scale the window would end up having. This is
+       * needed to avoid jumping back and forth between the new and the old, since
+       * changing main monitor may cause the window to be resized so that it no
+       * longer have that same new main monitor. */
+      to = meta_screen_calculate_monitor_for_window (window->screen, window);
+    }
 
   if (from == to)
     return;