[librsvg: 1/2] (#763) Add auto width/height for rect element

[Marge Bot <marge-bot src gnome org>]

commit 6ab5f9beba5f9260d88f81a0f71c3f626f264efd
Author: Madds H <madds hollandart io>
Date:   Thu Jul 8 17:21:23 2021 -0500

    (#763) Add auto width/height for rect element
    
    Part-of: <https://gitlab.gnome.org/GNOME/librsvg/-/merge_requests/566>

 src/shapes.rs          | 15 +++++++++++----
 tests/src/reference.rs | 13 +++++++++++++
 2 files changed, 24 insertions(+), 4 deletions(-)
---
diff --git a/src/shapes.rs b/src/shapes.rs
index aee7dc4d..731c433c 100644
--- a/src/shapes.rs
+++ b/src/shapes.rs
@@ -407,8 +407,8 @@ impl BasicShape for Line {
 pub struct Rect {
     x: Length<Horizontal>,
     y: Length<Vertical>,
-    width: ULength<Horizontal>,
-    height: ULength<Vertical>,
+    width: LengthOrAuto<Horizontal>,
+    height: LengthOrAuto<Vertical>,
 
     // Radiuses for rounded corners
     rx: Option<Length<Horizontal>>,
@@ -440,8 +440,15 @@ impl BasicShape for Rect {
     fn make_shape(&self, params: &NormalizeParams) -> ShapeDef {
         let x = self.x.to_user(params);
         let y = self.y.to_user(params);
-        let w = self.width.to_user(params);
-        let h = self.height.to_user(params);
+
+        let w = match self.width {
+            LengthOrAuto::Length(l) => l.to_user(&params),
+            LengthOrAuto::Auto => 0.0,
+        };
+        let h = match self.height {
+            LengthOrAuto::Length(l) => l.to_user(&params),
+            LengthOrAuto::Auto => 0.0,
+        };
 
         let specified_rx = self.rx.map(|l| l.to_user(params));
         let specified_ry = self.ry.map(|l| l.to_user(params));
diff --git a/tests/src/reference.rs b/tests/src/reference.rs
index 3efa3db5..658f9ccb 100644
--- a/tests/src/reference.rs
+++ b/tests/src/reference.rs
@@ -335,3 +335,16 @@ test_compare_render_output!(
       <rect x="10" y="10" width="10" height="10" fill="lime"/>
     </svg>"##,
 );
+
+test_compare_render_output!(
+    rect_auto_width_height,
+    30,
+    30,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
+    <svg xmlns="http://www.w3.org/2000/svg"; width="30" height="30">
+      <rect x="10" y="10" width="auto" height="auto" fill="lime"/>
+    </svg>"##,
+    br##"<?xml version="1.0" encoding="UTF-8"?>
+    <svg xmlns="http://www.w3.org/2000/svg"; width="30" height="30">
+    </svg>"##
+);