Implement a parent check in sectionRowIndex

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 57 matching lines @@
   HTMLTableRowElement* candidate = rows->item(0);
   for (int i = 0; candidate; i++, candidate = rows->item(i)) {
     if (this == candidate)
       return i;
   }
 
   return -1;
 }
 
 int HTMLTableRowElement::sectionRowIndex() const {
+  ContainerNode* maybeTable = parentNode();
+  if (!(maybeTable && (isHTMLTableSectionElement(maybeTable) ||
+                       isHTMLTableElement(maybeTable))))
+    return -1;
   int rIndex = 0;
   const Node* n = this;
   do {
     n = n->previousSibling();
     if (n && isHTMLTableRowElement(*n))
       ++rIndex;

[foolip, 2016/10/11 09:28:45]

Does this counting match exactly what the spec says, with the rows collection?
HTMLTableRowsCollection::rowAfter is pretty complicated, suggesting not. Can you
file an issue for this?

[rwlbuis, 2016/10/11 16:54:48]

Yes, implementation seems pretty/too simple atm, filed crbug.com/654777.

   } while (n);
 
   return rIndex;
 }
 
 HTMLElement* HTMLTableRowElement::insertCell(int index,
                                              ExceptionState& exceptionState) {
   HTMLCollection* children = cells();
   int numCells = children ? children->length() : 0;
   if (index < -1 || index > numCells) {
@@ skipping 27 matching lines @@
                             ") is outside the range [0, " +
                             String::number(numCells) + ").");
   }
 }
 
 HTMLCollection* HTMLTableRowElement::cells() {
   return ensureCachedCollection<HTMLCollection>(TRCells);
 }
 
 }  // namespace blink