Make sectionRowIndex be more conforming to spec

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

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights
  * reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 37 matching lines @@
 bool HTMLTableRowElement::hasLegalLinkAttribute(
     const QualifiedName& name) const {
   return name == backgroundAttr ||
          HTMLTablePartElement::hasLegalLinkAttribute(name);
 }
 
 const QualifiedName& HTMLTableRowElement::subResourceAttributeName() const {
   return backgroundAttr;
 }
 
+static int findIndexInRowCollection(HTMLCollection* rows,

[tkent, 2016/10/27 02:31:28]

nit: Because |rows| isn't nullptr and it isn't modified, the argument type
should be |const HTMLCollection&|.

+                                    const HTMLTableRowElement* target) {

[tkent, 2016/10/27 02:31:28]

nit: |target| isn't nullptr.  The argument type should be |const
HTMLTableRowElement&|.

+  Element* candidate = rows->item(0);
+  for (int i = 0; candidate; i++, candidate = rows->item(i)) {
+    if (target == candidate)
+      return i;
+  }
+  return -1;
+}
+
 int HTMLTableRowElement::rowIndex() const {
   ContainerNode* maybeTable = parentNode();
   if (maybeTable && isHTMLTableSectionElement(maybeTable)) {
     // Skip THEAD, TBODY and TFOOT.
     maybeTable = maybeTable->parentNode();
   }
   if (!(maybeTable && isHTMLTableElement(maybeTable)))
     return -1;
-
-  HTMLTableRowsCollection* rows = toHTMLTableElement(maybeTable)->rows();
-  HTMLTableRowElement* candidate = rows->item(0);
-  for (int i = 0; candidate; i++, candidate = rows->item(i)) {
-    if (this == candidate)
-      return i;
-  }
-
-  return -1;
+  return findIndexInRowCollection(toHTMLTableElement(maybeTable)->rows(), this);
 }
 
 int HTMLTableRowElement::sectionRowIndex() const {
   ContainerNode* maybeTable = parentNode();
-  if (!(maybeTable && (isHTMLTableSectionElement(maybeTable) ||
-                       isHTMLTableElement(maybeTable))))
+  if (!maybeTable)
     return -1;
-  int rIndex = 0;
-  const Node* n = this;
-  do {
-    n = n->previousSibling();
-    if (n && isHTMLTableRowElement(*n))
-      ++rIndex;
-  } while (n);
-
-  return rIndex;
+  HTMLCollection* rows = nullptr;
+  if (isHTMLTableSectionElement(maybeTable))
+    rows = toHTMLTableSectionElement(maybeTable)->rows();
+  else if (isHTMLTableElement(maybeTable))
+    rows = toHTMLTableElement(maybeTable)->rows();
+  if (!rows)
+    return -1;
+  return findIndexInRowCollection(rows, this);
 }
 
 HTMLElement* HTMLTableRowElement::insertCell(int index,
                                              ExceptionState& exceptionState) {
   HTMLCollection* children = cells();
   int numCells = children ? children->length() : 0;
   if (index < -1 || index > numCells) {
     exceptionState.throwDOMException(
         IndexSizeError, "The value provided (" + String::number(index) +
                             ") is outside the range [-1, " +
@@ skipping 32 matching lines @@
   // 3. Remove the indexth element in the cells collection from its parent.
   Element* cell = children->item(index);
   HTMLElement::removeChild(cell, exceptionState);
 }
 
 HTMLCollection* HTMLTableRowElement::cells() {
   return ensureCachedCollection<HTMLCollection>(TRCells);
 }
 
 }  // namespace blink