Resolve percentage in use against the instance's viewport element

https://bugs.webkit.org/show_bug.cgi?id=256702 rdar://problem/109565397 Reviewed by Simon Fraser. This patch aligns WebKit with Blink / Chromium and Gecko / Firefox. Merge: https://chromium.googlesource.com/chromium/src/+/b34ff6fe2d5842a63e2c66f68f050f0cf9163010 In RenderSVGTransformableContainer::calculateLocalTransform, 'x' and 'y' were resolved against the original (corresponding) element. For a `use` nested within a `symbol`, this would mean that when were going to look up the viewport element, we would return the outer `symbol` element and thus fail to get a viewport. Use the instance element to setup the SVGLengthContext instead. * Source/WebCore/rendering/svg/LegacyRenderSVGTransformableContainer.cpp: (LegacyRenderSVGTransformableContainer::calculateLocalTransform): Use 'element' rather than 'useElement' * LayoutTests/svg/custom/use-nested-symbol-viewport.html: Add Test Case * LayoutTests/svg/custom/use-nested-symbol-viewport-expected.html: Add Test Case Expectation Canonical link: https://commits.webkit.org/264596@main
WebKit · May 26, 2023 · 590f8fc · 590f8fc
1 parent b3b7524
commit 590f8fc
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diff --git a/LayoutTests/svg/custom/use-nested-symbol-viewport-expected.html b/LayoutTests/svg/custom/use-nested-symbol-viewport-expected.html
@@ -0,0 +1,2 @@
+<!DOCTYPE html>
+<div style="width: 100px; height: 100px; background-color: green"></div>
diff --git a/LayoutTests/svg/custom/use-nested-symbol-viewport.html b/LayoutTests/svg/custom/use-nested-symbol-viewport.html
@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<svg width="200" height="100">
+  <rect width="100" height="100" fill="red"/>
+  <symbol id="inner">
+    <rect width="100" height="100"/>
+  </symbol>
+  <symbol id="outer">
+    <rect x="50%" width="100" height="100" fill="red"/>
+    <use xlink:href="#inner" x="50%" fill="green"/>
+  </symbol>
+  <use xlink:href="#outer" transform="translate(-100, 0)"/>
+</svg>
diff --git a/Source/WebCore/rendering/svg/LegacyRenderSVGTransformableContainer.cpp b/Source/WebCore/rendering/svg/LegacyRenderSVGTransformableContainer.cpp
@@ -1,7 +1,7 @@
 /*
  * Copyright (C) 2004, 2005 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006 Rob Buis <buis@kde.org>
- * Copyright (C) 2009 Google, Inc.
+ * Copyright (C) 2009-2016 Google, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -58,7 +58,7 @@ bool LegacyRenderSVGTransformableContainer::calculateLocalTransform()
     }
 
     if (useElement) {
-        SVGLengthContext lengthContext(useElement);
+        SVGLengthContext lengthContext(&element);
         FloatSize translation(useElement->x().value(lengthContext), useElement->y().value(lengthContext));
         if (translation != m_lastTranslation)
             m_needsTransformUpdate = true;