parser/htmlparser/src/nsHTMLTags.cpp
author Ed Morley <bmo@edmorley.co.uk>
Mon, 05 Mar 2012 15:22:28 +0000
changeset 88257 c8503cd3aac40cf000266e7fa4ce001d192062aa
parent 88241 afeafc02c1de285724fd42424d5453a388c97657
child 88607 bd1bb076db6e306391d9f1df4ad10429c0c45dae
permissions -rw-r--r--
Backout afeafc02c1de, dfae37833c9b & f9f51c726fa7 (bug 729940 parts 1-3) for talos regressions

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla Communicator client code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "mozilla/Util.h"

#include "nsHTMLTags.h"
#include "nsCRT.h"
#include "nsReadableUtils.h"
#include "nsString.h"
#include "nsStaticAtom.h"
#include "nsUnicharUtils.h"

using namespace mozilla;

// C++ sucks! There's no way to do this with a macro, at least not
// that I know, if you know how to do this with a macro then please do
// so...
static const PRUnichar sHTMLTagUnicodeName_a[] =
  {'a', '\0'};
static const PRUnichar sHTMLTagUnicodeName_abbr[] =
  {'a', 'b', 'b', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_acronym[] =
  {'a', 'c', 'r', 'o', 'n', 'y', 'm', '\0'};
static const PRUnichar sHTMLTagUnicodeName_address[] =
  {'a', 'd', 'd', 'r', 'e', 's', 's', '\0'};
static const PRUnichar sHTMLTagUnicodeName_applet[] =
  {'a', 'p', 'p', 'l', 'e', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_area[] =
  {'a', 'r', 'e', 'a', '\0'};
static const PRUnichar sHTMLTagUnicodeName_article[] =
  {'a', 'r', 't', 'i', 'c', 'l', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_aside[] =
  {'a', 's', 'i', 'd', 'e', '\0'};
#if defined(MOZ_MEDIA)
static const PRUnichar sHTMLTagUnicodeName_audio[] =
  {'a', 'u', 'd', 'i', 'o', '\0'};
#endif
static const PRUnichar sHTMLTagUnicodeName_b[] =
  {'b', '\0'};
static const PRUnichar sHTMLTagUnicodeName_base[] =
  {'b', 'a', 's', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_basefont[] =
  {'b', 'a', 's', 'e', 'f', 'o', 'n', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_bdo[] =
  {'b', 'd', 'o', '\0'};
static const PRUnichar sHTMLTagUnicodeName_bgsound[] =
  {'b', 'g', 's', 'o', 'u', 'n', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_big[] =
  {'b', 'i', 'g', '\0'};
static const PRUnichar sHTMLTagUnicodeName_blink[] =
  {'b', 'l', 'i', 'n', 'k', '\0'};
static const PRUnichar sHTMLTagUnicodeName_blockquote[] =
  {'b', 'l', 'o', 'c', 'k', 'q', 'u', 'o', 't', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_body[] =
  {'b', 'o', 'd', 'y', '\0'};
static const PRUnichar sHTMLTagUnicodeName_br[] =
  {'b', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_button[] =
  {'b', 'u', 't', 't', 'o', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_canvas[] =
  {'c', 'a', 'n', 'v', 'a', 's', '\0'};
static const PRUnichar sHTMLTagUnicodeName_caption[] =
  {'c', 'a', 'p', 't', 'i', 'o', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_center[] =
  {'c', 'e', 'n', 't', 'e', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_cite[] =
  {'c', 'i', 't', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_code[] =
  {'c', 'o', 'd', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_col[] =
  {'c', 'o', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_colgroup[] =
  {'c', 'o', 'l', 'g', 'r', 'o', 'u', 'p', '\0'};
static const PRUnichar sHTMLTagUnicodeName_counter[] =
  {'c', 'o', 'u', 'n', 't', 'e', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_datalist[] =
  {'d', 'a', 't', 'a', 'l', 'i', 's', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_dd[] =
  {'d', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_del[] =
  {'d', 'e', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_dfn[] =
  {'d', 'f', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_dir[] =
  {'d', 'i', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_div[] =
  {'d', 'i', 'v', '\0'};
static const PRUnichar sHTMLTagUnicodeName_dl[] =
  {'d', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_dt[] =
  {'d', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_em[] =
  {'e', 'm', '\0'};
static const PRUnichar sHTMLTagUnicodeName_embed[] =
  {'e', 'm', 'b', 'e', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_fieldset[] =
  {'f', 'i', 'e', 'l', 'd', 's', 'e', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_figcaption[] =
  {'f', 'i', 'g', 'c', 'a', 'p', 't', 'i', 'o', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_figure[] =
  {'f', 'i', 'g', 'u', 'r', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_font[] =
  {'f', 'o', 'n', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_footer[] =
  {'f', 'o', 'o', 't', 'e', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_form[] =
  {'f', 'o', 'r', 'm', '\0'};
static const PRUnichar sHTMLTagUnicodeName_frame[] =
  {'f', 'r', 'a', 'm', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_frameset[] =
  {'f', 'r', 'a', 'm', 'e', 's', 'e', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_h1[] =
  {'h', '1', '\0'};
static const PRUnichar sHTMLTagUnicodeName_h2[] =
  {'h', '2', '\0'};
static const PRUnichar sHTMLTagUnicodeName_h3[] =
  {'h', '3', '\0'};
static const PRUnichar sHTMLTagUnicodeName_h4[] =
  {'h', '4', '\0'};
static const PRUnichar sHTMLTagUnicodeName_h5[] =
  {'h', '5', '\0'};
static const PRUnichar sHTMLTagUnicodeName_h6[] =
  {'h', '6', '\0'};
static const PRUnichar sHTMLTagUnicodeName_head[] =
  {'h', 'e', 'a', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_header[] =
  {'h', 'e', 'a', 'd', 'e', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_hgroup[] =
  {'h', 'g', 'r', 'o', 'u', 'p', '\0'};
static const PRUnichar sHTMLTagUnicodeName_hr[] =
  {'h', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_html[] =
  {'h', 't', 'm', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_i[] =
  {'i', '\0'};
static const PRUnichar sHTMLTagUnicodeName_iframe[] =
  {'i', 'f', 'r', 'a', 'm', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_image[] =
  {'i', 'm', 'a', 'g', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_img[] =
  {'i', 'm', 'g', '\0'};
static const PRUnichar sHTMLTagUnicodeName_input[] =
  {'i', 'n', 'p', 'u', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_ins[] =
  {'i', 'n', 's', '\0'};
static const PRUnichar sHTMLTagUnicodeName_kbd[] =
  {'k', 'b', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_keygen[] =
  {'k', 'e', 'y', 'g', 'e', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_label[] =
  {'l', 'a', 'b', 'e', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_legend[] =
  {'l', 'e', 'g', 'e', 'n', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_li[] =
  {'l', 'i', '\0'};
static const PRUnichar sHTMLTagUnicodeName_link[] =
  {'l', 'i', 'n', 'k', '\0'};
static const PRUnichar sHTMLTagUnicodeName_listing[] =
  {'l', 'i', 's', 't', 'i', 'n', 'g', '\0'};
static const PRUnichar sHTMLTagUnicodeName_map[] =
  {'m', 'a', 'p', '\0'};
static const PRUnichar sHTMLTagUnicodeName_mark[] =
  {'m', 'a', 'r', 'k', '\0'};
static const PRUnichar sHTMLTagUnicodeName_marquee[] =
  {'m', 'a', 'r', 'q', 'u', 'e', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_menu[] =
  {'m', 'e', 'n', 'u', '\0'};
static const PRUnichar sHTMLTagUnicodeName_menuitem[] =
  {'m', 'e', 'n', 'u', 'i', 't', 'e', 'm', '\0'};
static const PRUnichar sHTMLTagUnicodeName_meta[] =
  {'m', 'e', 't', 'a', '\0'};
static const PRUnichar sHTMLTagUnicodeName_multicol[] =
  {'m', 'u', 'l', 't', 'i', 'c', 'o', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_nav[] =
  {'n', 'a', 'v', '\0'};
static const PRUnichar sHTMLTagUnicodeName_nobr[] =
  {'n', 'o', 'b', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_noembed[] =
  {'n', 'o', 'e', 'm', 'b', 'e', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_noframes[] =
  {'n', 'o', 'f', 'r', 'a', 'm', 'e', 's', '\0'};
static const PRUnichar sHTMLTagUnicodeName_noscript[] =
  {'n', 'o', 's', 'c', 'r', 'i', 'p', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_object[] =
  {'o', 'b', 'j', 'e', 'c', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_ol[] =
  {'o', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_optgroup[] =
  {'o', 'p', 't', 'g', 'r', 'o', 'u', 'p', '\0'};
static const PRUnichar sHTMLTagUnicodeName_option[] =
  {'o', 'p', 't', 'i', 'o', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_output[] =
  {'o', 'u', 't', 'p', 'u', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_p[] =
  {'p', '\0'};
static const PRUnichar sHTMLTagUnicodeName_param[] =
  {'p', 'a', 'r', 'a', 'm', '\0'};
static const PRUnichar sHTMLTagUnicodeName_plaintext[] =
  {'p', 'l', 'a', 'i', 'n', 't', 'e', 'x', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_pre[] =
  {'p', 'r', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_progress[] =
  {'p', 'r', 'o', 'g', 'r', 'e', 's', 's', '\0'};
static const PRUnichar sHTMLTagUnicodeName_q[] =
  {'q', '\0'};
static const PRUnichar sHTMLTagUnicodeName_s[] =
  {'s', '\0'};
static const PRUnichar sHTMLTagUnicodeName_samp[] =
  {'s', 'a', 'm', 'p', '\0'};
static const PRUnichar sHTMLTagUnicodeName_script[] =
  {'s', 'c', 'r', 'i', 'p', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_section[] =
  {'s', 'e', 'c', 't', 'i', 'o', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_select[] =
  {'s', 'e', 'l', 'e', 'c', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_small[] =
  {'s', 'm', 'a', 'l', 'l', '\0'};
#if defined(MOZ_MEDIA)
static const PRUnichar sHTMLTagUnicodeName_source[] =
  {'s', 'o', 'u', 'r', 'c', 'e', '\0'};
#endif
static const PRUnichar sHTMLTagUnicodeName_spacer[] =
  {'s', 'p', 'a', 'c', 'e', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_span[] =
  {'s', 'p', 'a', 'n', '\0'};
static const PRUnichar sHTMLTagUnicodeName_strike[] =
  {'s', 't', 'r', 'i', 'k', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_strong[] =
  {'s', 't', 'r', 'o', 'n', 'g', '\0'};
static const PRUnichar sHTMLTagUnicodeName_style[] =
  {'s', 't', 'y', 'l', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_sub[] =
  {'s', 'u', 'b', '\0'};
static const PRUnichar sHTMLTagUnicodeName_sup[] =
  {'s', 'u', 'p', '\0'};
static const PRUnichar sHTMLTagUnicodeName_table[] =
  {'t', 'a', 'b', 'l', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_tbody[] =
  {'t', 'b', 'o', 'd', 'y', '\0'};
static const PRUnichar sHTMLTagUnicodeName_td[] =
  {'t', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_textarea[] =
  {'t', 'e', 'x', 't', 'a', 'r', 'e', 'a', '\0'};
static const PRUnichar sHTMLTagUnicodeName_tfoot[] =
  {'t', 'f', 'o', 'o', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_th[] =
  {'t', 'h', '\0'};
static const PRUnichar sHTMLTagUnicodeName_thead[] =
  {'t', 'h', 'e', 'a', 'd', '\0'};
static const PRUnichar sHTMLTagUnicodeName_title[] =
  {'t', 'i', 't', 'l', 'e', '\0'};
static const PRUnichar sHTMLTagUnicodeName_tr[] =
  {'t', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_tt[] =
  {'t', 't', '\0'};
static const PRUnichar sHTMLTagUnicodeName_u[] =
  {'u', '\0'};
static const PRUnichar sHTMLTagUnicodeName_ul[] =
  {'u', 'l', '\0'};
static const PRUnichar sHTMLTagUnicodeName_var[] =
  {'v', 'a', 'r', '\0'};
#if defined(MOZ_MEDIA)
static const PRUnichar sHTMLTagUnicodeName_video[] =
  {'v', 'i', 'd', 'e', 'o', '\0'};
#endif
static const PRUnichar sHTMLTagUnicodeName_wbr[] =
  {'w', 'b', 'r', '\0'};
static const PRUnichar sHTMLTagUnicodeName_xmp[] =
  {'x', 'm', 'p', '\0'};

// static array of unicode tag names
#define HTML_TAG(_tag, _classname) sHTMLTagUnicodeName_##_tag,
#define HTML_HTMLELEMENT_TAG(_tag) sHTMLTagUnicodeName_##_tag,
#define HTML_OTHER(_tag)
const PRUnichar* const nsHTMLTags::sTagUnicodeTable[] = {
#include "nsHTMLTagList.h"
};
#undef HTML_TAG
#undef HTML_HTMLELEMENT_TAG
#undef HTML_OTHER

// static array of tag atoms
nsIAtom* nsHTMLTags::sTagAtomTable[eHTMLTag_userdefined - 1];

PRInt32 nsHTMLTags::gTableRefCount;
PLHashTable* nsHTMLTags::gTagTable;
PLHashTable* nsHTMLTags::gTagAtomTable;


// PRUnichar* -> id hash
static PLHashNumber
HTMLTagsHashCodeUCPtr(const void *key)
{
  const PRUnichar *str = (const PRUnichar *)key;

  return nsCRT::HashCode(str);
}

static PRIntn
HTMLTagsKeyCompareUCPtr(const void *key1, const void *key2)
{
  const PRUnichar *str1 = (const PRUnichar *)key1;
  const PRUnichar *str2 = (const PRUnichar *)key2;

  return nsCRT::strcmp(str1, str2) == 0;
}

// nsIAtom* -> id hash
static PLHashNumber
HTMLTagsHashCodeAtom(const void *key)
{
  return NS_PTR_TO_INT32(key) >> 2;
}

#define NS_HTMLTAG_NAME_MAX_LENGTH 10

#define HTML_TAG(_tag, _classname) NS_STATIC_ATOM_BUFFER(Atombuffer_##_tag, #_tag)
#define HTML_HTMLELEMENT_TAG(_tag) NS_STATIC_ATOM_BUFFER(Atombuffer_##_tag, #_tag)
#define HTML_OTHER(_tag)
#include "nsHTMLTagList.h"
#undef HTML_TAG
#undef HTML_HTMLELEMENT_TAG
#undef HTML_OTHER


// static
nsresult
nsHTMLTags::AddRefTable(void)
{
  // static array of tag StaticAtom structs
#define HTML_TAG(_tag, _classname) NS_STATIC_ATOM(Atombuffer_##_tag, &nsHTMLTags::sTagAtomTable[eHTMLTag_##_tag - 1]),
#define HTML_HTMLELEMENT_TAG(_tag) NS_STATIC_ATOM(Atombuffer_##_tag, &nsHTMLTags::sTagAtomTable[eHTMLTag_##_tag - 1]),
#define HTML_OTHER(_tag)
  static const nsStaticAtom sTagAtoms_info[] = {
#include "nsHTMLTagList.h"
  };
#undef HTML_TAG
#undef HTML_HTMLELEMENT_TAG
#undef HTML_OTHER

  if (gTableRefCount++ == 0) {
    // Fill in our static atom pointers
    NS_RegisterStaticAtoms(sTagAtoms_info, ArrayLength(sTagAtoms_info));


    NS_ASSERTION(!gTagTable && !gTagAtomTable, "pre existing hash!");

    gTagTable = PL_NewHashTable(64, HTMLTagsHashCodeUCPtr,
                                HTMLTagsKeyCompareUCPtr, PL_CompareValues,
                                nsnull, nsnull);
    NS_ENSURE_TRUE(gTagTable, NS_ERROR_OUT_OF_MEMORY);

    gTagAtomTable = PL_NewHashTable(64, HTMLTagsHashCodeAtom,
                                    PL_CompareValues, PL_CompareValues,
                                    nsnull, nsnull);
    NS_ENSURE_TRUE(gTagAtomTable, NS_ERROR_OUT_OF_MEMORY);

    // Fill in gTagTable with the above static PRUnichar strings as
    // keys and the value of the corresponding enum as the value in
    // the table.

    PRInt32 i;
    for (i = 0; i < NS_HTML_TAG_MAX; ++i) {
      PL_HashTableAdd(gTagTable, sTagUnicodeTable[i],
                      NS_INT32_TO_PTR(i + 1));

      PL_HashTableAdd(gTagAtomTable, sTagAtomTable[i],
                      NS_INT32_TO_PTR(i + 1));
    }



#if defined(DEBUG) && defined(NS_STATIC_ATOM_USE_WIDE_STRINGS)
    {
      // let's verify that all names in the the table are lowercase...
      for (i = 0; i < NS_HTML_TAG_MAX; ++i) {
        nsAutoString temp1((PRUnichar*)sTagAtoms_info[i].mStringBuffer->Data());
        nsAutoString temp2((PRUnichar*)sTagAtoms_info[i].mStringBuffer->Data());
        ToLowerCase(temp1);
        NS_ASSERTION(temp1.Equals(temp2), "upper case char in table");
      }

      // let's verify that all names in the unicode strings above are
      // correct.
      for (i = 0; i < NS_HTML_TAG_MAX; ++i) {
        nsAutoString temp1(sTagUnicodeTable[i]);
        nsAutoString temp2((PRUnichar*)sTagAtoms_info[i].mStringBuffer->Data());
        NS_ASSERTION(temp1.Equals(temp2), "Bad unicode tag name!");
      }

      // let's verify that NS_HTMLTAG_NAME_MAX_LENGTH is correct
      PRUint32 maxTagNameLength = 0;
      for (i = 0; i < NS_HTML_TAG_MAX; ++i) {
        PRUint32 len = nsCRT::strlen(sTagUnicodeTable[i]);
        maxTagNameLength = NS_MAX(len, maxTagNameLength);        
      }
      NS_ASSERTION(maxTagNameLength == NS_HTMLTAG_NAME_MAX_LENGTH,
                   "NS_HTMLTAG_NAME_MAX_LENGTH not set correctly!");
    }
#endif
  }

  return NS_OK;
}

// static
void
nsHTMLTags::ReleaseTable(void)
{
  if (0 == --gTableRefCount) {
    if (gTagTable) {
      // Nothing to delete/free in this table, just destroy the table.

      PL_HashTableDestroy(gTagTable);
      PL_HashTableDestroy(gTagAtomTable);
      gTagTable = nsnull;
      gTagAtomTable = nsnull;
    }
  }
}

// static
nsHTMLTag
nsHTMLTags::LookupTag(const nsAString& aTagName)
{
  PRUint32 length = aTagName.Length();

  if (length > NS_HTMLTAG_NAME_MAX_LENGTH) {
    return eHTMLTag_userdefined;
  }

  PRUnichar buf[NS_HTMLTAG_NAME_MAX_LENGTH + 1];

  nsAString::const_iterator iter;
  PRUint32 i = 0;
  PRUnichar c;

  aTagName.BeginReading(iter);

  // Fast lowercasing-while-copying of ASCII characters into a
  // PRUnichar buffer

  while (i < length) {
    c = *iter;

    if (c <= 'Z' && c >= 'A') {
      c |= 0x20; // Lowercase the ASCII character.
    }

    buf[i] = c; // Copy ASCII character.

    ++i;
    ++iter;
  }

  buf[i] = 0;

  return CaseSensitiveLookupTag(buf);
}

#ifdef DEBUG
void
nsHTMLTags::TestTagTable()
{
     const PRUnichar *tag;
     nsHTMLTag id;
     nsCOMPtr<nsIAtom> atom;

     nsHTMLTags::AddRefTable();
     // Make sure we can find everything we are supposed to
     for (int i = 0; i < NS_HTML_TAG_MAX; ++i) {
       tag = sTagUnicodeTable[i];
       id = LookupTag(nsDependentString(tag));
       NS_ASSERTION(id != eHTMLTag_userdefined, "can't find tag id");
       const PRUnichar* check = GetStringValue(id);
       NS_ASSERTION(0 == nsCRT::strcmp(check, tag), "can't map id back to tag");

       nsAutoString uname(tag);
       ToUpperCase(uname);
       NS_ASSERTION(id == LookupTag(uname), "wrong id");

       NS_ASSERTION(id == CaseSensitiveLookupTag(tag), "wrong id");

       atom = do_GetAtom(tag);
       NS_ASSERTION(id == CaseSensitiveLookupTag(atom), "wrong id");
       NS_ASSERTION(atom == GetAtom(id), "can't map id back to atom");
     }

     // Make sure we don't find things that aren't there
     id = LookupTag(NS_LITERAL_STRING("@"));
     NS_ASSERTION(id == eHTMLTag_userdefined, "found @");
     id = LookupTag(NS_LITERAL_STRING("zzzzz"));
     NS_ASSERTION(id == eHTMLTag_userdefined, "found zzzzz");

     atom = do_GetAtom("@");
     id = CaseSensitiveLookupTag(atom);
     NS_ASSERTION(id == eHTMLTag_userdefined, "found @");
     atom = do_GetAtom("zzzzz");
     id = CaseSensitiveLookupTag(atom);
     NS_ASSERTION(id == eHTMLTag_userdefined, "found zzzzz");

     tag = GetStringValue((nsHTMLTag) 0);
     NS_ASSERTION(!tag, "found enum 0");
     tag = GetStringValue((nsHTMLTag) -1);
     NS_ASSERTION(!tag, "found enum -1");
     tag = GetStringValue((nsHTMLTag) (NS_HTML_TAG_MAX + 1));
     NS_ASSERTION(!tag, "found past max enum");

     atom = GetAtom((nsHTMLTag) 0);
     NS_ASSERTION(!atom, "found enum 0");
     atom = GetAtom((nsHTMLTag) -1);
     NS_ASSERTION(!atom, "found enum -1");
     atom = GetAtom((nsHTMLTag) (NS_HTML_TAG_MAX + 1));
     NS_ASSERTION(!atom, "found past max enum");

     ReleaseTable();
}

#endif // DEBUG