[mutter/cherry-pick-56939abd] cursor-renderer/native: Add a means to disable HW cursors

[Jonas Ådahl <jadahl src gnome org>]

commit 5d0c26631b3f0d163a89bc914f02cba385558be2
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Fri Dec 10 10:57:29 2021 +0100

    cursor-renderer/native: Add a means to disable HW cursors
    
    When dealing with a faulty hardware or bugs in the driver, it might be
    interesting to force the use of software cursors for debugging purposes.
    
    Add a debug environment variable MUTTER_DEBUG_DISABLE_HW_CURSORS to
    disable hardware cursors and force using software cursors.
    
    Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2046
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2150>
    
    
    (cherry picked from commit 56939abd2f1691eea9edf85cb715ebf275944e7e)

 src/backends/native/meta-cursor-renderer-native.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/src/backends/native/meta-cursor-renderer-native.c 
b/src/backends/native/meta-cursor-renderer-native.c
index 3143d2512b..d9e4a7e1d7 100644
--- a/src/backends/native/meta-cursor-renderer-native.c
+++ b/src/backends/native/meta-cursor-renderer-native.c
@@ -1864,7 +1864,10 @@ meta_cursor_renderer_native_new (MetaBackend        *backend,
 
   priv->backend = backend;
 
-  init_hw_cursor_support (cursor_renderer_native);
+  if (g_strcmp0 (getenv ("MUTTER_DEBUG_DISABLE_HW_CURSORS"), "1"))
+    init_hw_cursor_support (cursor_renderer_native);
+  else
+    g_message ("Disabling hardware cursors because MUTTER_DEBUG_DISABLE_HW_CURSORS is set");
 
   return cursor_renderer_native;
 }