Improve canBeAnchorNode() for PositionInFlatTree constructor

third_party/WebKit/Source/core/editing/Position.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 17 matching lines @@
 #include "core/dom/shadow/ElementShadow.h"
 #include "core/editing/EditingUtilities.h"
 #include "core/editing/TextAffinity.h"
 #include "wtf/text/CString.h"
 #include <stdio.h>
 #include <ostream> // NOLINT
 
 namespace blink {
 
 #if DCHECK_IS_ON()
-static bool canBeAnchorNode(Node* node)
+template <typename Strategy>
+static bool canBeAnchorNode(Node*);
+
+template <>
+bool canBeAnchorNode<EditingStrategy>(Node* node)
 {
     return !node || !node->isPseudoElement();
 }
+
+template <>
+bool canBeAnchorNode<EditingInFlatTreeStrategy>(Node* node)
+{
+    return canBeAnchorNode<EditingStrategy>(node) && node->canParticipateInFlatTree();
+}
 #endif
 
 template <typename Strategy>
 const TreeScope* PositionTemplate<Strategy>::commonAncestorTreeScope(const PositionTemplate<Strategy>& a, const PositionTemplate<Strategy>& b)
 {
     if (!a.computeContainerNode() || !b.computeContainerNode())
         return nullptr;
     return a.computeContainerNode()->treeScope().commonAncestorTreeScope(b.computeContainerNode()->treeScope());
 }
 
@@ skipping 30 matching lines @@
         DCHECK(m_anchorType == PositionAnchorType::BeforeAnchor || m_anchorType == PositionAnchorType::AfterAnchor);
         return;
     }
     if (m_anchorNode->isDocumentNode()) {
         // Since |RangeBoundaryPoint| can't represent before/after Document, we
         // should not use them.
         DCHECK(isBeforeChildren() || isAfterChildren()) << m_anchorType;
         return;
     }
 #if DCHECK_IS_ON()
-    DCHECK(canBeAnchorNode(m_anchorNode.get()));
+    DCHECK(canBeAnchorNode<Strategy>(m_anchorNode.get())) << m_anchorNode;
 #endif
     DCHECK_NE(m_anchorType, PositionAnchorType::OffsetInAnchor);
 }
 
 template <typename Strategy>
 PositionTemplate<Strategy>::PositionTemplate(Node* anchorNode, int offset)
     : m_anchorNode(anchorNode)
     , m_offset(offset)
     , m_anchorType(PositionAnchorType::OffsetInAnchor)
 {
     if (m_anchorNode)
         DCHECK_GE(offset, 0);
     else
         DCHECK_EQ(offset, 0);
 #if DCHECK_IS_ON()
-    DCHECK(canBeAnchorNode(m_anchorNode.get()));
+    DCHECK(canBeAnchorNode<Strategy>(m_anchorNode.get())) << m_anchorNode;
 #endif
 }
 
 template <typename Strategy>
 PositionTemplate<Strategy>::PositionTemplate(const PositionTemplate& other)
     : m_anchorNode(other.m_anchorNode)
     , m_offset(other.m_offset)
     , m_anchorType(other.m_anchorType)
 {
 }
@@ skipping 584 matching lines @@
 
 void showTree(const blink::Position* pos)
 {
     if (pos)
         pos->showTreeForThis();
     else
         fprintf(stderr, "Cannot showTree for (nil)\n");
 }
 
 #endif