window.c: Fix regression in window positioning when a window is

restored from a tiled state.

This reverts 051b8d2, which aimed to fix apps fullscreening to the
wrong monitor if they had been originally maximized and dragged
between monitors.

The fix unfortunately breaks the window's 'saved' unconstrained
position. For example, when using keyboard shortcuts to un-tile
(push in the opposite direction of the active tile), the size is
restored, but the position is not.

Instead, translate the saved x and y position relative to the new
monitor before calling maximize_internal().

This fixes the original problem without impacting keybindings and
other actions that remove the tiled state.

Fixes #809.
Fixes #810.

Author: mtwebster

src/core/window.c

@@ -3532,44 +3532,46 @@ meta_window_tile (MetaWindow   *window,
   else
     directions = META_MAXIMIZE_VERTICAL;
 
+  MetaRectangle *maybe_saved_rect = NULL;
 
-  MetaRectangle existing_rect, work_area, tile_area;
-  meta_window_get_frame_rect(window, &existing_rect);
-  meta_window_get_work_area_for_monitor(window, window->tile_monitor_number, &work_area);
-  tile_area = existing_rect;
-
-  switch (tile_mode)
+  if (window->saved_tile_mode == META_TILE_NONE && window->display->grab_op != META_GRAB_OP_NONE)
     {
-    case META_TILE_LEFT:
-      tile_area.x = work_area.x;
-      tile_area.y = work_area.y;
-      break;
-
-    case META_TILE_RIGHT:
-      tile_area.x = work_area.x + work_area.width - existing_rect.width;
-      tile_area.y = work_area.y;
-      break;
-
-    case META_TILE_TOP:
-      tile_area.x = work_area.x;
-      tile_area.y = work_area.y;
-      break;
+      maybe_saved_rect = &window->display->grab_initial_window_pos;
+    }
+  else
+  if (window->saved_tile_mode != META_TILE_NONE)
+    {
+      maybe_saved_rect = &window->saved_rect;
+    }
 
-    case META_TILE_BOTTOM:
-      tile_area.x = work_area.x;
-      tile_area.y = work_area.y + work_area.height - existing_rect.height;
-      break;
+  // If the saved restore position is not on the target monitor, translate it
+  // it so that fullscreening (which un-tiles) happens on the correct monitor.
+  if (maybe_saved_rect != NULL)
+    {
+      MetaRectangle target_work_area;
+      meta_window_get_work_area_for_monitor (window, window->tile_monitor_number, &target_work_area);
 
-    default:
-      tile_area.x = work_area.x + (work_area.width - existing_rect.width) / 2;
-      tile_area.y = work_area.y + (work_area.height - existing_rect.height) / 2;
-      break;
-  }
+      if (!meta_rectangle_overlap (maybe_saved_rect, &target_work_area))
+        {
+          MetaBackend *backend = meta_get_backend ();
+          MetaMonitorManager *monitor_manager =
+            meta_backend_get_monitor_manager (backend);
+          const MetaLogicalMonitor *old_monitor =
+            meta_monitor_manager_get_logical_monitor_from_rect (monitor_manager,
+                                                                maybe_saved_rect);
+
+          if (old_monitor)
+            {
+              MetaRectangle old_work_area;
+              meta_window_get_work_area_for_monitor (window, old_monitor->number, &old_work_area);
 
-  window->saved_rect = tile_area;
-  window->unconstrained_rect = tile_area;
+              maybe_saved_rect->x += target_work_area.x - old_work_area.x;
+              maybe_saved_rect->y += target_work_area.y - old_work_area.y;
+            }
+        }
+    }
 
-  meta_window_maximize_internal (window, directions, &window->saved_rect);
+  meta_window_maximize_internal (window, directions, maybe_saved_rect);
   meta_display_update_tile_preview (window->display, FALSE);
 
   if ((!window->htile_match || window->htile_match != window->display->grab_window) &&