[gtk] Fix gtk_widget_compute_transform

[Matthias Clasen <matthiasc src gnome org>]

commit 93b47c12d7550c347ad453cf11cfc3cd8917c379
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Feb 19 19:29:56 2019 -0500

    Fix gtk_widget_compute_transform
    
    We were collecting all the transforms from widget
    up to ancestor, and then trying to collect the
    ones from target to ancestor, but failing.

 gtk/gtkwidget.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index f22581d0ab..fb376adea2 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -11283,7 +11283,7 @@ gtk_widget_compute_transform (GtkWidget         *widget,
     graphene_matrix_t inv;
 
     graphene_matrix_init_identity (&down_transform);
-
+    parent = target;
     while (parent != ancestor)
       {
         graphene_matrix_multiply (&down_transform, &parent->priv->transform, &down_transform);