[mutter] backends: Protect from reentrancy in meta_cursor_sprite_load_from_theme

[Carlos Garnacho <carlosg src gnome org>]

commit 1790320ba3063ed1661cd7ca1e8590ac4ab901a6
Author: Carlos Garnacho <carlosg gnome org>
Date:   Fri Nov 17 14:07:20 2017 +0100

    backends: Protect from reentrancy in meta_cursor_sprite_load_from_theme
    
    This function is supposedly not failable, so just move the theme_dirty
    flag clearing to the beginning of the function. Protects against cases
    where requesting a cursor image may result in it being loaded and set
    as a texture, which emits ::texture-changed, which may end up requesting
    the cursor image again.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=754806

 src/backends/meta-cursor.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/backends/meta-cursor.c b/src/backends/meta-cursor.c
index ccd0ab0..beeee76 100644
--- a/src/backends/meta-cursor.c
+++ b/src/backends/meta-cursor.c
@@ -229,6 +229,8 @@ meta_cursor_sprite_load_from_theme (MetaCursorSprite *self)
 
   g_assert (self->cursor != META_CURSOR_NONE);
 
+  self->theme_dirty = FALSE;
+
   /* We might be reloading with a different scale. If so clear the old data. */
   if (self->xcursor_images)
     {
@@ -244,8 +246,6 @@ meta_cursor_sprite_load_from_theme (MetaCursorSprite *self)
 
   image = meta_cursor_sprite_get_current_frame_image (self);
   meta_cursor_sprite_load_from_xcursor_image (self, image);
-
-  self->theme_dirty = FALSE;
 }
 
 MetaCursorSprite *