SVG Image intrinsic size should be used if css style size is 'auto'

third_party/WebKit/Source/core/layout/svg/LayoutSVGImage.cpp

 /*
  * Copyright (C) 2006 Alexander Kellett <lypanov@kde.org>
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2007, 2008, 2009 Rob Buis <buis@kde.org>
  * Copyright (C) 2009 Google, Inc.
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Patrick Gansterer <paroga@paroga.com>
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 48 matching lines @@
     ImageQualityController::remove(*this);
     m_imageResource->shutdown();
     LayoutSVGModelObject::willBeDestroyed();
 }
 
 void LayoutSVGImage::updateBoundingBox()
 {
     FloatRect oldBoundaries = m_objectBoundingBox;
 
     SVGLengthContext lengthContext(element());
+    ImageResource* cachedImage = m_imageResource->cachedImage();
+    FloatSize intrinsicSize;
+    if (cachedImage && !cachedImage->errorOccurred())
+        intrinsicSize = FloatSize(cachedImage->getImage()->size());

[fs, 2016/08/16 12:43:08]

I checked the spec, and these seem to be the relevant sections:

https://svgwg.org/svg2-draft/embedded.html#Placement
https://svgwg.org/svg2-draft/geometry.html#Sizing

(those can be added to the description)

I notice that the initial value is set to '0' for the attribute (the former
link) while it is 'auto' for the properties. Should probably get that cleared up
in the spec. (This will affect existing content too.) I'm not 100% sure that the
different descriptions of 'auto' are useful (and equivalent either), so that's
one other thing to consider also filing a spec issue about. (I'd go with the
description from the second link, since that seems to just refer to CSS sizing.)

[Shanmuga Pandi, 2016/08/19 07:20:28]

I filed a spec bug:
https://github.com/w3c/svgwg/issues/237

+
     m_objectBoundingBox = FloatRect(
         lengthContext.valueForLength(styleRef().svgStyle().x(), styleRef(), SVGLengthMode::Width),
         lengthContext.valueForLength(styleRef().svgStyle().y(), styleRef(), SVGLengthMode::Height),
-        lengthContext.valueForLength(styleRef().width(), styleRef(), SVGLengthMode::Width),
-        lengthContext.valueForLength(styleRef().height(), styleRef(), SVGLengthMode::Height));
+        styleRef().width().isAuto() ? intrinsicSize.width() : lengthContext.valueForLength(styleRef().width(), styleRef(), SVGLengthMode::Width),
+        styleRef().height().isAuto() ? intrinsicSize.height() : lengthContext.valueForLength(styleRef().height(), styleRef(), SVGLengthMode::Height));
+
     m_needsBoundariesUpdate |= oldBoundaries != m_objectBoundingBox;
 }
 
 void LayoutSVGImage::layout()
 {
     ASSERT(needsLayout());
     LayoutAnalyzer::Scope analyzer(*this);
 
     // Invalidate all resources of this client if our layout changed.
     if (everHadLayout() && selfNeedsLayout())
@@ skipping 55 matching lines @@
     return false;
 }
 
 void LayoutSVGImage::imageChanged(WrappedImagePtr, const IntRect*)
 {
     // Notify parent resources that we've changed. This also invalidates
     // references from resources (filters) that may have a cached
     // representation of this image/layout object.
     LayoutSVGResourceContainer::markForLayoutAndParentResourceInvalidation(this, false);
 
+    if (styleRef().width().isAuto() || styleRef().height().isAuto()) {
+        FloatRect oldBoundaries = m_objectBoundingBox;
+        updateBoundingBox();
+        FloatRect newBoundaries = m_objectBoundingBox;
+        if (oldBoundaries.size() != newBoundaries.size()) {

[fs, 2016/08/16 12:43:08]

Just make updateBoundingBox() return a bool instead.

[Shanmuga Pandi, 2016/08/19 07:20:28]

Done.

+            setNeedsLayoutAndFullPaintInvalidation(LayoutInvalidationReason::SizeChanged);

[fs, 2016/08/16 12:43:08]

Maybe just make this setNeedsLayout and then a fall-through to mark for paint
invalidation.

Also, make sure there's a test for this code-path.

[Shanmuga Pandi, 2016/08/19 07:20:28]

Done.

+            return;
+        }
+    }
+
     setShouldDoFullPaintInvalidation();
 }
 
 void LayoutSVGImage::addOutlineRects(Vector<LayoutRect>& rects, const LayoutPoint&, IncludeBlockVisualOverflowOrNot) const
 {
     // this is called from paint() after the localTransform has already been applied
     rects.append(LayoutRect(paintInvalidationRectInLocalSVGCoordinates()));
 }
 
 } // namespace blink