[librsvg/librsvg-2.50] (#554): Do not ignore the viewport in the geometry_for_layer() APIs

[Federico Mena Quintero <federico src gnome org>]

commit 6ebdebf43a92aff635646f19e1ccfd4c263ab535
Author: Federico Mena Quintero <federico gnome org>
Date:   Mon Sep 28 19:58:19 2020 -0500

    (#554): Do not ignore the viewport in the geometry_for_layer() APIs
    
    Convert the final bounds to be relative to the starting transform.
    
    Fixes https://gitlab.gnome.org/GNOME/librsvg/-/issues/554

 librsvg_crate/tests/intrinsic_dimensions.rs |  1 -
 rsvg_internals/src/drawing_ctx.rs           | 14 +++++++++-----
 2 files changed, 9 insertions(+), 6 deletions(-)
---
diff --git a/librsvg_crate/tests/intrinsic_dimensions.rs b/librsvg_crate/tests/intrinsic_dimensions.rs
index 3e05ead1..db06cd3c 100644
--- a/librsvg_crate/tests/intrinsic_dimensions.rs
+++ b/librsvg_crate/tests/intrinsic_dimensions.rs
@@ -81,7 +81,6 @@ fn root_geometry_with_percent_viewport() {
     assert_eq!((ink_r, logical_r), (rect, rect));
 }
 
-#[cfg(ignore)]
 #[test]
 fn layer_geometry_with_offset_viewport() {
     let svg = load_svg(
diff --git a/rsvg_internals/src/drawing_ctx.rs b/rsvg_internals/src/drawing_ctx.rs
index ff0aa5a8..38b23299 100644
--- a/rsvg_internals/src/drawing_ctx.rs
+++ b/rsvg_internals/src/drawing_ctx.rs
@@ -179,9 +179,16 @@ pub fn draw_tree(
 
     let cascaded = CascadedValues::new_from_node(&node);
 
+    let transform = Transform::from(cr.get_matrix());
+    let mut bbox = BoundingBox::new().with_transform(transform);
+
     let mut draw_ctx = DrawingCtx::new(cr, viewport, dpi, measuring, testing, drawsub_stack);
 
-    draw_ctx.draw_node_from_stack(&node, acquired_nodes, &cascaded, false)
+    let content_bbox = draw_ctx.draw_node_from_stack(&node, acquired_nodes, &cascaded, false)?;
+
+    bbox.insert(&content_bbox);
+
+    Ok(bbox)
 }
 
 impl DrawingCtx {
@@ -214,10 +221,7 @@ impl DrawingCtx {
         let viewport = viewport.translate((-viewport.x0, -viewport.y0));
         let vbox = ViewBox::from(viewport);
 
-        let initial_viewport = Viewport {
-            transform,
-            vbox,
-        };
+        let initial_viewport = Viewport { transform, vbox };
 
         let mut viewport_stack = Vec::new();
         viewport_stack.push(initial_viewport);