Align HTMLImageElement relevant mutations to spec

third_party/WebKit/Source/core/html/HTMLImageElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 251 matching lines @@
 
 void HTMLImageElement::parseAttribute(const QualifiedName& name, const AtomicString& oldValue, const AtomicString& value)
 {
     if (name == altAttr || name == titleAttr) {
         if (userAgentShadowRoot()) {
             Element* text = userAgentShadowRoot()->getElementById("alttext");
             String value = altText();
             if (text && text->textContent() != value)
                 text->setTextContent(altText());
         }
-    } else if (name == srcAttr || name == srcsetAttr || name == sizesAttr) {
+    } else if (name == srcAttr || ((name == srcsetAttr || name == sizesAttr) && (value != oldValue))) {
         selectSourceURL(ImageLoader::UpdateIgnorePreviousError);
     } else if (name == usemapAttr) {
         setIsLink(!value.isNull());
     } else if (RuntimeEnabledFeatures::referrerPolicyAttributeEnabled() && name == referrerpolicyAttr) {
         m_referrerPolicy = ReferrerPolicyDefault;
         if (!value.isNull())
             SecurityPolicy::referrerPolicyFromString(value, &m_referrerPolicy);
     } else {
         HTMLElement::parseAttribute(name, oldValue, value);
     }
@@ skipping 109 matching lines @@
     if (document().isActive()) {
         ImageCandidate candidate = findBestFitImageFromPictureParent();
         if (!candidate.isEmpty()) {
             setBestFitURLAndDPRFromImageCandidate(candidate);
             imageWasModified = true;
         }
     }
 
     // If we have been inserted from a layoutObject-less document,
     // our loader may have not fetched the image, so do it now.
-    if ((insertionPoint->inDocument() && !imageLoader().image()) || imageWasModified)
+    if ((insertionPoint->inDocument() && !imageLoader().image()) || imageWasModified || isHTMLPictureElement(insertionPoint))
         imageLoader().updateFromElement(ImageLoader::UpdateNormal, m_referrerPolicy);
 
     return HTMLElement::insertedInto(insertionPoint);
 }
 
-void HTMLImageElement::removedFrom(ContainerNode* insertionPoint)
+void HTMLImageElement::removedFrom(ContainerNode* insertionPoint, Node* next)
 {
     if (!m_form || NodeTraversal::highestAncestorOrSelf(*m_form.get()) != NodeTraversal::highestAncestorOrSelf(*this))
         resetFormOwner();
     if (m_listener)
         document().mediaQueryMatcher().removeViewportListener(m_listener);
-    HTMLElement::removedFrom(insertionPoint);
+    HTMLElement::removedFrom(insertionPoint, next);
+
+    if (isHTMLPictureElement(insertionPoint)) {
+        // This is diverging from the spec because we don't want to trigger spurious downloads of fallback images.
+        // See https://github.com/ResponsiveImagesCG/picture-element/issues/274
+        m_bestFitImageURL = AtomicString();
+        imageLoader().updateFromElement(ImageLoader::UpdateNormal, m_referrerPolicy);
+    }
 }
 
 int HTMLImageElement::width()
 {
     if (inActiveDocument())
         document().updateLayoutIgnorePendingStylesheets();
 
     if (!layoutObject()) {
         // check the attribute first for an explicit pixel value
         bool ok;
@@ skipping 382 matching lines @@
 {
     ImageResource* image = cachedImage();
     if (!image)
         return IntSize();
     LayoutSize lSize = image->imageSize(LayoutObject::shouldRespectImageOrientation(layoutObject()), 1.0f);
     ASSERT(lSize.fraction().isZero());
     return IntSize(lSize.width(), lSize.height());
 }
 
 }