Throw exceptions for charnum == getNumberOfChars in get{...}OfChar APIs

Source/core/svg/SVGTextContentElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Rob Buis <buis@kde.org>
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 103 matching lines @@
     if (nchars > numberOfChars - charnum)
         nchars = numberOfChars - charnum;
 
     return SVGTextQuery(layoutObject()).subStringLength(charnum, nchars);
 }
 
 PassRefPtrWillBeRawPtr<SVGPointTearOff> SVGTextContentElement::getStartPositionOfChar(unsigned charnum, ExceptionState& exceptionState)
 {
     document().updateLayoutIgnorePendingStylesheets();
 
-    if (charnum > getNumberOfChars()) {
+    if (charnum >= getNumberOfChars()) {
         exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexExceedsMaximumBound("charnum", charnum, getNumberOfChars()));
         return nullptr;
     }
 
     FloatPoint point = SVGTextQuery(layoutObject()).startPositionOfCharacter(charnum);
     return SVGPointTearOff::create(SVGPoint::create(point), 0, PropertyIsNotAnimVal);
 }
 
 PassRefPtrWillBeRawPtr<SVGPointTearOff> SVGTextContentElement::getEndPositionOfChar(unsigned charnum, ExceptionState& exceptionState)
 {
     document().updateLayoutIgnorePendingStylesheets();
 
-    if (charnum > getNumberOfChars()) {
+    if (charnum >= getNumberOfChars()) {
         exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexExceedsMaximumBound("charnum", charnum, getNumberOfChars()));
         return nullptr;
     }
 
     FloatPoint point = SVGTextQuery(layoutObject()).endPositionOfCharacter(charnum);
     return SVGPointTearOff::create(SVGPoint::create(point), 0, PropertyIsNotAnimVal);
 }
 
 PassRefPtrWillBeRawPtr<SVGRectTearOff> SVGTextContentElement::getExtentOfChar(unsigned charnum, ExceptionState& exceptionState)
 {
     document().updateLayoutIgnorePendingStylesheets();
 
-    if (charnum > getNumberOfChars()) {
+    if (charnum >= getNumberOfChars()) {
         exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexExceedsMaximumBound("charnum", charnum, getNumberOfChars()));
         return nullptr;
     }
 
     FloatRect rect = SVGTextQuery(layoutObject()).extentOfCharacter(charnum);
     return SVGRectTearOff::create(SVGRect::create(rect), 0, PropertyIsNotAnimVal);
 }
 
 float SVGTextContentElement::getRotationOfChar(unsigned charnum, ExceptionState& exceptionState)
 {
     document().updateLayoutIgnorePendingStylesheets();
 
-    if (charnum > getNumberOfChars()) {
+    if (charnum >= getNumberOfChars()) {
         exceptionState.throwDOMException(IndexSizeError, ExceptionMessages::indexExceedsMaximumBound("charnum", charnum, getNumberOfChars()));
         return 0.0f;
     }
 
     return SVGTextQuery(layoutObject()).rotationOfCharacter(charnum);
 }
 
 int SVGTextContentElement::getCharNumAtPosition(PassRefPtrWillBeRawPtr<SVGPointTearOff> point, ExceptionState& exceptionState)
 {
     document().updateLayoutIgnorePendingStylesheets();
@@ skipping 84 matching lines @@
 
     if (!layoutObject->isSVGText() && !layoutObject->isSVGInline())
         return nullptr;
 
     SVGElement* element = toSVGElement(layoutObject->node());
     ASSERT(element);
     return isSVGTextContentElement(*element) ? toSVGTextContentElement(element) : 0;
 }
 
 }