[librsvg] drawing_ctx: use iterator instead of recursive function

[Paolo Borelli <pborelli src gnome org>]

commit d91ca5a66f3e8141728bbd00ef39bd377cdbfbb1
Author: Paolo Borelli <pborelli gnome org>
Date:   Mon Dec 30 21:04:30 2019 +0100

    drawing_ctx: use iterator instead of recursive function

 rsvg_internals/src/drawing_ctx.rs | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)
---
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index 63122c74..a9f60bf5 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -163,7 +163,9 @@ impl DrawingCtx {
         };
 
         if let Some(node) = node {
-            draw_ctx.add_node_and_ancestors_to_stack(node);
+            for n in node.ancestors() {
+                draw_ctx.drawsub_stack.push(n.clone());
+            }
         }
 
         draw_ctx
@@ -876,13 +878,6 @@ impl DrawingCtx {
 
         res
     }
-
-    pub fn add_node_and_ancestors_to_stack(&mut self, node: &RsvgNode) {
-        self.drawsub_stack.push(node.clone());
-        if let Some(ref parent) = node.parent() {
-            self.add_node_and_ancestors_to_stack(parent);
-        }
-    }
 }
 
 #[derive(Debug)]