SVG object with same idrefs get conflicted even they are under different shadow root

third_party/WebKit/Source/core/svg/SVGTreeScopeResources.cpp

+#include "core/svg/SVGTreeScopeResources.h"
+
+#include "core/dom/Element.h"
+#include "core/dom/TreeScope.h"
+#include "wtf/text/AtomicString.h"
+
+namespace blink {
+
+SVGTreeScopeResources::SVGTreeScopeResources(TreeScope* treeScope)
+    : m_treeScope(treeScope)
+{
+    // Whenever an object of SVGTreeScopeResources is created, to keep the code behave as before,
+    // the document should also have an instance of SVGDocumentExtensions created.
+    // Thus below lines are added
+    if (!treeScope->document().svgExtensions())
+        treeScope->document().accessSVGExtensions();
+}
+SVGTreeScopeResources::~SVGTreeScopeResources()
+{
+}
+void SVGTreeScopeResources::addResource(const AtomicString& id, LayoutSVGResourceContainer* resource)
+{
+    DCHECK(resource);
+
+    if (id.isEmpty())
+        return;
+    // Replaces resource if already present, to handle potential id changes
+    m_resources.set(id, resource);
+}
+
+void SVGTreeScopeResources::removeResource(const AtomicString& id)
+{
+    if (id.isEmpty())
+        return;
+
+    m_resources.remove(id);
+}
+
+LayoutSVGResourceContainer* SVGTreeScopeResources::resourceById(const AtomicString& id) const
+{
+    if (id.isEmpty())
+        return nullptr;
+    return m_resources.get(id);
+}
+void SVGTreeScopeResources::addPendingResource(const AtomicString& id, blink::Element* element)
+{
+    DCHECK(element);
+    DCHECK(element->inShadowIncludingDocument());
+
+    if (id.isEmpty())
+        return;
+
+    HeapHashMap<AtomicString, Member<SVGPendingElements>>::AddResult result = m_pendingResources.add(id, nullptr);
+    if (result.isNewEntry)
+        result.storedValue->value = new SVGPendingElements;
+    result.storedValue->value->add(element);
+
+    element->setHasPendingResources();
+}
+
+bool SVGTreeScopeResources::hasPendingResource(const AtomicString& id) const
+{
+    if (id.isEmpty())
+        return false;
+
+    return m_pendingResources.contains(id);
+}
+
+bool SVGTreeScopeResources::isElementPendingResources(Element* element) const
+{
+    // This algorithm takes time proportional to the number of pending resources and need not.
+    // If performance becomes an issue we can keep a counted set of elements and answer the question efficiently.
+
+    DCHECK(element);
+
+    for (const auto& entry : m_pendingResources) {
+        SVGPendingElements* elements = entry.value.get();
+        DCHECK(elements);
+
+        if (elements->contains(element))
+            return true;
+    }
+    return false;
+}
+
+bool SVGTreeScopeResources::isElementPendingResource(Element* element, const AtomicString& id) const
+{
+    DCHECK(element);
+
+    if (!hasPendingResource(id))
+        return false;
+
+    return m_pendingResources.get(id)->contains(element);
+}
+
+void SVGTreeScopeResources::clearHasPendingResourcesIfPossible(Element* element)
+{
+    if (!isElementPendingResources(element))
+        element->clearHasPendingResources();
+}
+
+void SVGTreeScopeResources::removeElementFromPendingResources(Element* element)
+{
+    DCHECK(element);
+
+    // Remove the element from pending resources.
+    if (!m_pendingResources.isEmpty() && element->hasPendingResources()) {
+        Vector<AtomicString> toBeRemoved;
+        for (const auto& entry : m_pendingResources) {
+            SVGPendingElements* elements = entry.value.get();
+            DCHECK(elements);
+            DCHECK(!elements->isEmpty());
+
+            elements->remove(element);
+            if (elements->isEmpty())
+                toBeRemoved.append(entry.key);
+        }
+
+        clearHasPendingResourcesIfPossible(element);
+
+        // We use the removePendingResource function here because it deals with set lifetime correctly.
+        for (const AtomicString& id : toBeRemoved)
+            removePendingResource(id);
+    }
+
+    // Remove the element from pending resources that were scheduled for removal.
+    if (!m_pendingResourcesForRemoval.isEmpty()) {
+        Vector<AtomicString> toBeRemoved;
+        for (const auto& entry : m_pendingResourcesForRemoval) {
+            SVGPendingElements* elements = entry.value.get();
+            DCHECK(elements);
+            DCHECK(!elements->isEmpty());
+
+            elements->remove(element);
+            if (elements->isEmpty())
+                toBeRemoved.append(entry.key);
+        }
+
+        // We use the removePendingResourceForRemoval function here because it deals with set lifetime correctly.
+        for (const AtomicString& id : toBeRemoved)
+            removePendingResourceForRemoval(id);
+    }
+}
+
+SVGTreeScopeResources::SVGPendingElements* SVGTreeScopeResources::removePendingResource(const AtomicString& id)
+{
+    DCHECK(m_pendingResources.contains(id));
+    return m_pendingResources.take(id);
+}
+
+SVGTreeScopeResources::SVGPendingElements* SVGTreeScopeResources::removePendingResourceForRemoval(const AtomicString& id)
+{
+    DCHECK(m_pendingResourcesForRemoval.contains(id));
+    return m_pendingResourcesForRemoval.take(id);
+}
+
+void SVGTreeScopeResources::markPendingResourcesForRemoval(const AtomicString& id)
+{
+    if (id.isEmpty())
+        return;
+
+    DCHECK(!m_pendingResourcesForRemoval.contains(id));
+
+    Member<SVGPendingElements> existing = m_pendingResources.take(id);
+    if (existing && !existing->isEmpty())
+        m_pendingResourcesForRemoval.add(id, existing.release());
+}
+
+Element* SVGTreeScopeResources::removeElementFromPendingResourcesForRemoval(const AtomicString& id)
+{
+    if (id.isEmpty())
+        return nullptr;
+
+    SVGPendingElements* resourceSet = m_pendingResourcesForRemoval.get(id);
+    if (!resourceSet || resourceSet->isEmpty())
+        return nullptr;
+
+    SVGPendingElements::iterator firstElement = resourceSet->begin();
+    Element* element = *firstElement;
+
+    resourceSet->remove(firstElement);
+
+    if (resourceSet->isEmpty())
+        removePendingResourceForRemoval(id);
+
+    return element;
+}
+DEFINE_TRACE(SVGTreeScopeResources)
+{
+    visitor->trace(m_treeScope);
+    visitor->trace(m_pendingResources);
+    visitor->trace(m_pendingResourcesForRemoval);
+}
+}