[mutter] backends: Do not set up the root cursor on invisible window pointers

[Carlos Garnacho <carlosg src gnome org>]

commit 3067dab84ce4ea57d7fb9e43d593ef183d9a6487
Author: Carlos Garnacho <carlosg gnome org>
Date:   Mon Nov 20 13:08:06 2017 +0100

    backends: Do not set up the root cursor on invisible window pointers
    
    Commit b1a0bf891 broke the previous logic that we would only fallback
    to the root cursor if 1) windows are not interactable or 2) no window
    cursor is currently set (i.e. not hovering over any window). Now it
    will set up the root cursor if it's NULL, which breaks clients
    explicitly setting an invisible cursor. This commit restaurates the
    previous behavior.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754806

 src/backends/meta-cursor-tracker.c |   11 ++++-------
 1 files changed, 4 insertions(+), 7 deletions(-)
---
diff --git a/src/backends/meta-cursor-tracker.c b/src/backends/meta-cursor-tracker.c
index f1562a2..b29a726 100644
--- a/src/backends/meta-cursor-tracker.c
+++ b/src/backends/meta-cursor-tracker.c
@@ -66,13 +66,10 @@ update_displayed_cursor (MetaCursorTracker *tracker)
   MetaDisplay *display = meta_get_display ();
   MetaCursorSprite *cursor = NULL;
 
-  if (display && meta_display_windows_are_interactable (display))
-    {
-      if (tracker->has_window_cursor)
-        cursor = tracker->window_cursor;
-    }
-
-  if (!cursor)
+  if (display && meta_display_windows_are_interactable (display) &&
+      tracker->has_window_cursor)
+    cursor = tracker->window_cursor;
+  else
     cursor = tracker->root_cursor;
 
   if (tracker->displayed_cursor == cursor)