[librsvg: 30/38] render_layer: make consistent with get_geometry_for_layer

[Federico Mena Quintero <federico src gnome org>]

commit f623f458d7a9a63711cbd1d79a1e1433dc70e2b1
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Sep 28 19:19:00 2020 -0500

    render_layer: make consistent with get_geometry_for_layer

 rsvg_internals/src/handle.rs | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)
---
diff --git a/rsvg_internals/src/handle.rs b/rsvg_internals/src/handle.rs
index 92c95706..9ec2b552 100644
--- a/rsvg_internals/src/handle.rs
+++ b/rsvg_internals/src/handle.rs
@@ -240,22 +240,17 @@ impl Handle {
     ) -> Result<(), RenderingError> {
         check_cairo_context(cr)?;
 
-        let root = self.document.root();
-
-        let mode = if let Some(id) = id {
-            let node = self.lookup_node(id).map_err(RenderingError::InvalidId)?;
+        cr.save();
 
-            DrawingMode::LimitToStack { node, root }
-        } else {
-            DrawingMode::OnlyNode(root)
-        };
+        let node = self.get_node_or_root(id)?;
+        let root = self.document.root();
 
-        cr.save();
+        let viewport = Rect::from(*viewport);
 
         let res = draw_tree(
-            mode,
+            DrawingMode::LimitToStack { node, root },
             cr,
-            Rect::from(*viewport),
+            viewport,
             dpi,
             false,
             is_testing,