From 96e074b38f4cebf0a2f44292dde2a77112b304a1 Mon Sep 17 00:00:00 2001
From: Andreas Kling <andreas@ladybird.org>
Date: Tue, 21 Jan 2025 01:06:38 +0100
Subject: [PATCH] LibWeb: Make SVGSVGElement.getElementById() return Element?
 (nullable)

This is wrong in the spec, and there's already a bug open.
---
 Libraries/LibWeb/SVG/SVGSVGElement.idl                    | 3 ++-
 Tests/LibWeb/Text/expected/SVG/svg-svg-getElementById.txt | 1 +
 Tests/LibWeb/Text/input/SVG/svg-svg-getElementById.html   | 8 ++++++++
 3 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 Tests/LibWeb/Text/expected/SVG/svg-svg-getElementById.txt
 create mode 100644 Tests/LibWeb/Text/input/SVG/svg-svg-getElementById.html

diff --git a/Libraries/LibWeb/SVG/SVGSVGElement.idl b/Libraries/LibWeb/SVG/SVGSVGElement.idl
index d7c368cbee3..b59c24e73ca 100644
--- a/Libraries/LibWeb/SVG/SVGSVGElement.idl
+++ b/Libraries/LibWeb/SVG/SVGSVGElement.idl
@@ -29,7 +29,8 @@ interface SVGSVGElement : SVGGraphicsElement {
     SVGTransform createSVGTransform();
     [FIXME] SVGTransform createSVGTransformFromMatrix(optional DOMMatrix2DInit matrix = {});
 
-    Element getElementById(DOMString elementId);
+    // NOTE: The spec says this returns `Element` but that's a bug: https://github.com/w3c/svgwg/issues/923
+    Element? getElementById(DOMString elementId);
 
     // Deprecated methods that have no effect when called,
     // but which are kept for compatibility reasons.
diff --git a/Tests/LibWeb/Text/expected/SVG/svg-svg-getElementById.txt b/Tests/LibWeb/Text/expected/SVG/svg-svg-getElementById.txt
new file mode 100644
index 00000000000..b2c18efad46
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/SVG/svg-svg-getElementById.txt
@@ -0,0 +1 @@
+PASS: true
diff --git a/Tests/LibWeb/Text/input/SVG/svg-svg-getElementById.html b/Tests/LibWeb/Text/input/SVG/svg-svg-getElementById.html
new file mode 100644
index 00000000000..0a072ce46f1
--- /dev/null
+++ b/Tests/LibWeb/Text/input/SVG/svg-svg-getElementById.html
@@ -0,0 +1,8 @@
+<script src="../include.js"></script>
+<svg id="svgRoot"></svg>
+<script>
+    test(() => {
+        const x = svgRoot.getElementById("x");
+        println(`PASS: ${x === null}`);
+    });
+</script>