From 44fcf33156d4a5c293c3137af0465b9179ecf436 Mon Sep 17 00:00:00 2001
From: Sebastian Wick <sebastian.wick@redhat.com>
Date: Wed, 13 Sep 2023 16:25:50 +0200
Subject: [PATCH] display: Handle entering NULL windows (desktop)

On X meta_window_handle_enter was called when the desktop window was
entered. On wayland the "desktop" is no window anymore. We still want to
inform the core that the desktop is focused, so it can unfocus windows
if focus-mode is mouse.

This commit prepares the core for handling a NULL windows to mean the
desktop.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3258>
---
 src/core/display.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/src/core/display.c b/src/core/display.c
index a4d102c64..67b210ac7 100644
--- a/src/core/display.c
+++ b/src/core/display.c
@@ -3806,21 +3806,21 @@ meta_display_flush_queued_window (MetaDisplay   *display,
 
 typedef struct
 {
+  MetaDisplay *display;
   MetaWindow *window;
   int pointer_x;
   int pointer_y;
 } MetaFocusData;
 
 static void
-focus_mouse_mode (MetaWindow *window,
-                  uint32_t    timestamp_ms)
+focus_mouse_mode (MetaDisplay *display,
+                  MetaWindow  *window,
+                  uint32_t     timestamp_ms)
 {
-  MetaDisplay *display = window->display;
-
-  if (window->override_redirect)
+  if (window && window->override_redirect)
     return;
 
-  if (window->type != META_WINDOW_DESKTOP)
+  if (window && window->type != META_WINDOW_DESKTOP)
     {
       meta_topic (META_DEBUG_FOCUS,
                   "Focusing %s at time %u.", window->desc, timestamp_ms);
@@ -3860,7 +3860,7 @@ focus_on_pointer_rest_callback (gpointer data)
 {
   MetaFocusData *focus_data = data;
   MetaWindow *window = focus_data->window;
-  MetaDisplay *display = window->display;
+  MetaDisplay *display = focus_data->display;
   MetaBackend *backend = backend_from_display (display);
   MetaCursorTracker *cursor_tracker = meta_backend_get_cursor_tracker (backend);
   graphene_point_t point;
@@ -3879,11 +3879,11 @@ focus_on_pointer_rest_callback (gpointer data)
       return G_SOURCE_CONTINUE;
     }
 
-  if (!meta_window_has_pointer (window))
+  if (window && !meta_window_has_pointer (window))
     goto out;
 
   timestamp_ms = meta_display_get_current_time_roundtrip (display);
-  focus_mouse_mode (window, timestamp_ms);
+  focus_mouse_mode (display, window, timestamp_ms);
 
  out:
   display->focus_timeout_id = 0;
@@ -3905,6 +3905,7 @@ queue_pointer_rest_callback (MetaDisplay *display,
   MetaFocusData *focus_data;
 
   focus_data = g_new (MetaFocusData, 1);
+  focus_data->display = display;
   focus_data->window = window;
   focus_data->pointer_x = pointer_x;
   focus_data->pointer_y = pointer_y;
@@ -3933,19 +3934,19 @@ meta_display_handle_window_enter (MetaDisplay *display,
     case G_DESKTOP_FOCUS_MODE_SLOPPY:
     case G_DESKTOP_FOCUS_MODE_MOUSE:
       display->mouse_mode = TRUE;
-      if (window->type != META_WINDOW_DOCK)
+      if (!window || window->type != META_WINDOW_DOCK)
         {
-          if (meta_prefs_get_focus_change_on_pointer_rest())
+          if (meta_prefs_get_focus_change_on_pointer_rest ())
             queue_pointer_rest_callback (display, window, root_x, root_y);
           else
-            focus_mouse_mode (window, timestamp_ms);
+            focus_mouse_mode (display, window, timestamp_ms);
         }
       break;
     case G_DESKTOP_FOCUS_MODE_CLICK:
       break;
     }
 
-  if (window->type == META_WINDOW_DOCK)
+  if (window && window->type == META_WINDOW_DOCK)
     meta_window_raise (window);
 }
 
@@ -3953,6 +3954,6 @@ void
 meta_display_handle_window_leave (MetaDisplay *display,
                                   MetaWindow  *window)
 {
-  if (window->type == META_WINDOW_DOCK && !window->has_focus)
+  if (window && window->type == META_WINDOW_DOCK && !window->has_focus)
     meta_window_lower (window);
 }