drupal/modules/filter/filter.test

<?php
// $Id$

class FilterAdminTestCase extends DrupalWebTestCase {
  public static function getInfo() {
    return array(
      'name' => t('Filter administration functionality'),
      'description' => t('Thoroughly test the administrative interface of the filter module.'),
      'group' => t('Filter'),
    );
  }

  /**
   * Test filter administration functionality.
   */
  function testFilterAdmin() {
    // URL filter.
    $first_filter = 2;
    // Line filter.
    $second_filter = 1;

    // Create users.
    $admin_user = $this->drupalCreateUser(array('administer filters'));
    $web_user = $this->drupalCreateUser(array('create page content'));
    $this->drupalLogin($admin_user);

    list($filtered, $full) = $this->checkFilterFormats();

    // Change default filter.
    $edit = array();
    $edit['default'] = $full;
    $this->drupalPost('admin/settings/formats', $edit, t('Save changes'));
    $this->assertText(t('Default format updated.'), t('Default filter updated successfully.'));

    $this->assertNoRaw('admin/settings/formats/delete/' . $full, t('Delete link not found.'));

    // Add an additional tag.
    $edit = array();
    $edit['allowed_html_1'] = '<a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd> <quote>';
    $this->drupalPost('admin/settings/formats/' . $filtered . '/configure', $edit, t('Save configuration'));
    $this->assertText(t('The configuration options have been saved.'), t('Allowed HTML tag added.'));

    $this->assertRaw(htmlentities($edit['allowed_html_1']), t('Tag displayed.'));

    $result = db_query('SELECT * FROM {cache_filter}')->fetchObject();
    $this->assertFalse($result, t('Cache cleared.'));

    // Reorder filters.
    $edit = array();
    $edit['weights[filter/' . $second_filter . ']'] = 1;
    $edit['weights[filter/' . $first_filter . ']'] = 2;
    $this->drupalPost('admin/settings/formats/' . $filtered . '/order', $edit, t('Save configuration'));
    $this->assertText(t('The filter ordering has been saved.'), t('Order saved successfully.'));

    $result = db_query('SELECT * FROM {filter} WHERE format = :format ORDER BY weight ASC', array(':format' => $filtered));
    $filters = array();
    foreach ($result as $filter) {
      if ($filter->delta == $second_filter || $filter->delta == $first_filter) {
        $filters[] = $filter;
      }
    }
    $this->assertTrue(($filters[0]->delta == $second_filter && $filters[1]->delta == $first_filter), t('Order confirmed.'));

    // Add filter.
    $edit = array();
    $edit['name'] = $this->randomName();
    $edit['roles[2]'] = TRUE;
    $edit['filters[filter/' . $second_filter . ']'] = TRUE;
    $edit['filters[filter/' . $first_filter . ']'] = TRUE;
    $this->drupalPost('admin/settings/formats/add', $edit, t('Save configuration'));
    $this->assertRaw(t('Added text format %format.', array('%format' => $edit['name'])), t('New filter created.'));

    $format = $this->getFilter($edit['name']);
    $this->assertNotNull($format, t('Format found in database.'));

    if ($format !== NULL) {
      $this->assertFieldByName('roles[2]', '', t('Role found.'));
      $this->assertFieldByName('filters[filter/' . $second_filter . ']', '', t('Line break filter found.'));
      $this->assertFieldByName('filters[filter/' . $first_filter . ']', '', t('Url filter found.'));

      // Delete new filter.
      $this->drupalPost('admin/settings/formats/delete/' . $format->format, array(), t('Delete'));
      $this->assertRaw(t('Deleted text format %format.', array('%format' => $edit['name'])), t('Format successfully deleted.'));
    }

    // Change default filter back.
    $edit = array();
    $edit['default'] = $filtered;
    $this->drupalPost('admin/settings/formats', $edit, t('Save changes'));
    $this->assertText(t('Default format updated.'), t('Default filter updated successfully.'));

    $this->assertNoRaw('admin/settings/formats/delete/' . $filtered, t('Delete link not found.'));

    // Allow authenticated users on full HTML.
    $edit = array();
    $edit['roles[2]'] = TRUE;
    $this->drupalPost('admin/settings/formats/' . $full, $edit, t('Save configuration'));
    $this->assertText(t('The text format settings have been updated.'), t('Full HTML format successfully updated.'));

    // Switch user.
    $this->drupalLogout();
    $this->drupalLogin($web_user);

    $this->drupalGet('node/add/page');
    $this->assertRaw('<option value="' . $full . '">Full HTML</option>', t('Full HTML filter accessible.'));

    // Use filtered HTML and see if it removes tags that are not allowed.
    $body = $this->randomName();
    $extra_text = 'text';

    $edit = array();
    $edit['title'] = $this->randomName();
    $edit['body[0][value]'] = $body . '<random>' . $extra_text . '</random>';
    $edit['body[0][value_format]'] = $filtered;
    $this->drupalPost('node/add/page', $edit, t('Save'));
    $this->assertRaw(t('Page %title has been created.', array('%title' => $edit['title'])), t('Filtered node created.'));

    $node = $this->drupalGetNodeByTitle($edit['title']);
    $this->assertTrue($node, t('Node found in database.'));

    $this->drupalGet('node/' . $node->nid);
    $this->assertText($body . $extra_text, t('Filter removed invalid tag.'));

    // Switch user.
    $this->drupalLogout();
    $this->drupalLogin($admin_user);

    // Clean up.
    // Allowed tags.
    $edit = array();
    $edit['allowed_html_1'] = '<a> <em> <strong> <cite> <code> <ul> <ol> <li> <dl> <dt> <dd>';
    $this->drupalPost('admin/settings/formats/' . $filtered . '/configure', $edit, t('Save configuration'));
    $this->assertText(t('The configuration options have been saved.'), t('Changes reverted.'));

    // Full HTML.
    $edit = array();
    $edit['roles[2]'] = FALSE;
    $this->drupalPost('admin/settings/formats/' . $full, $edit, t('Save configuration'));
    $this->assertText(t('The text format settings have been updated.'), t('Full HTML format successfully reverted.'));

    // Filter order.
    $edit = array();
    $edit['weights[filter/' . $second_filter . ']'] = 2;
    $edit['weights[filter/' . $first_filter . ']'] = 1;
    $this->drupalPost('admin/settings/formats/' . $filtered . '/order', $edit, t('Save configuration'));
    $this->assertText(t('The filter ordering has been saved.'), t('Order successfully reverted.'));
  }

  /**
   * Query the database to get the two basic formats.
   *
   * @return
   *   An array containing filtered and full filter ids.
   */
  function checkFilterFormats() {
    $result = db_query('SELECT format, name FROM {filter_format}');

    $filtered = -1;
    $full = -1;
    foreach ($result as $format) {
      if ($format->name == 'Filtered HTML') {
        $filtered = $format->format;
      }
      elseif ($format->name == 'Full HTML') {
        $full = $format->format;
      }
    }

    return array($filtered, $full);
  }

  /**
   * Get filter by name.
   *
   * @param $name
   *   Name of filter to find.
   * @return
   *   A filter object.
   */
  function getFilter($name) {
    return db_query("SELECT * FROM {filter_format} WHERE name = :name", array(':name' => $name))->fetchObject();
  }
}

class FilterTestCase extends DrupalWebTestCase {
  protected $format;

  public static function getInfo() {
    return array(
      'name' => t('Core filters'),
      'description' => t('Filter each filter individually: Convert URLs into links, Convert line breaks, Correct broken HTML, Escape all HTML, Limit allowed HTML tags.'),
      'group' => t('Filter'),
    );
  }

  function setUp() {
    parent::setUp();

    $admin_user = $this->drupalCreateUser(array('administer filters', 'create page content'));
    $this->drupalLogin($admin_user);
  }

  /**
   * Test the line break filter.
   */
  function testLineBreakFilter() {
    // Single line breaks should be changed to <br /> tags, while paragraphs
    // separated with double line breaks should be enclosed with <p></p> tags.
    $f = _filter_autop("aaa\nbbb\n\nccc");
    $this->assertEqual(str_replace("\n", '', $f), "<p>aaa<br />bbb</p><p>ccc</p>", t('Line breaking basic case.'));

    // Text within some contexts should not be processed.
    $f = _filter_autop("<script>aaa\nbbb\n\nccc</script>");
    $this->assertEqual($f, "<script>aaa\nbbb\n\nccc</script>", t('Line breaking -- do not break scripts.'));

    $f = _filter_autop('<p><div>  </div></p>');
    $this->assertEqual(substr_count($f, '<p>'), substr_count($f, '</p>'), t('Make sure line breaking produces matching paragraph tags.'));

    $f = _filter_autop('<div><p>  </p></div>');
    $this->assertEqual(substr_count($f, '<p>'), substr_count($f, '</p>'), t('Make sure line breaking produces matching paragraph tags.'));

    $f = _filter_autop('<blockquote><pre>aaa</pre></blockquote>');
    $this->assertEqual(substr_count($f, '<p>'), substr_count($f, '</p>'), t('Make sure line breaking produces matching paragraph tags.'));

    $limit = max(ini_get('pcre.backtrack_limit'), ini_get('pcre.recursion_limit'));
    $f = _filter_autop($this->randomName($limit));
    $this->assertNotEqual($f, '', t('Make sure line breaking can process long strings.'));
  }

  /**
   * Test limiting allowed tags, XSS prevention and adding 'nofollow' to links.
   *
   * XSS tests assume that script is dissallowed on default and src is allowed
   * on default, but on* and style are dissallowed.
   *
   * Script injection vectors mostly adopted from http://ha.ckers.org/xss.html.
   *
   * Relevant CVEs:
   * - CVE-2002-1806, ~CVE-2005-0682, ~CVE-2005-2106, CVE-2005-3973,
   *   CVE-2006-1226 (= rev. 1.112?), CVE-2008-0273, CVE-2008-3740.
   */
  function testHtmlFilter() {
    // Tag stripping, different ways to work around removal of HTML tags.
    $f = filter_xss('<script>alert(0)</script>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping -- simple script without special characters.'));

    $f = filter_xss('<script src="http://www.example.com" />');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping -- empty script with source.'));

    $f = filter_xss('<ScRipt sRc=http://www.example.com/>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- varying case.'));

    $f = filter_xss("<script\nsrc\n=\nhttp://www.example.com/\n>");
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- multiline tag.'));

    $f = filter_xss('<script/a src=http://www.example.com/a.js></script>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- non whitespace character after tag name.'));

    $f = filter_xss('<script/src=http://www.example.com/a.js></script>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- no space between tag and attribute.'));

    // Null between < and tag name works at least with IE6.
    $f = filter_xss("<\0scr\0ipt>alert(0)</script>");
    $this->assertNoNormalized($f, 'ipt', t('HTML tag stripping evasion -- breaking HTML with nulls.'));

    $f = filter_xss("<scrscriptipt src=http://www.example.com/a.js>");
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- filter just removing "script".'));

    $f = filter_xss('<<script>alert(0);//<</script>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- double opening brackets.'));

    $f = filter_xss('<script src=http://www.example.com/a.js?<b>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- no closing tag.'));

    // DRUPAL-SA-2008-047: This doesn't seem exploitable, but the filter should
    // work consistently.
    $f = filter_xss('<script>>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- double closing tag.'));

    $f = filter_xss('<script src=//www.example.com/.a>');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- no scheme or ending slash.'));

    $f = filter_xss('<script src=http://www.example.com/.a');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- no closing bracket.'));

    $f = filter_xss('<script src=http://www.example.com/ <');
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- opening instead of closing bracket.'));

    $f = filter_xss('<nosuchtag attribute="newScriptInjectionVector">');
    $this->assertNoNormalized($f, 'nosuchtag', t('HTML tag stripping evasion -- unknown tag.'));

    $f = filter_xss('<?xml:namespace ns="urn:schemas-microsoft-com:time">');
    $this->assertTrue(stripos($f, '<?xml') === FALSE, t('HTML tag stripping evasion -- starting with a question sign (processing instructions).'));

    $f = filter_xss('<t:set attributeName="innerHTML" to="&lt;script defer&gt;alert(0)&lt;/script&gt;">');
    $this->assertNoNormalized($f, 't:set', t('HTML tag stripping evasion -- colon in the tag name (namespaces\' tricks).'));

    $f = filter_xss('<img """><script>alert(0)</script>', array('img'));
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- a malformed image tag.'));

    $f = filter_xss('<blockquote><script>alert(0)</script></blockquote>', array('blockquote'));
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- script in a blockqoute.'));

    $f = filter_xss("<!--[if true]><script>alert(0)</script><![endif]-->");
    $this->assertNoNormalized($f, 'script', t('HTML tag stripping evasion -- script within a comment.'));

    // Dangerous attributes removal.
    $f = filter_xss('<p onmouseover="http://www.example.com/">', array('p'));
    $this->assertNoNormalized($f, 'onmouseover', t('HTML filter attributes removal -- events, no evasion.'));

    $f = filter_xss('<li style="list-style-image: url(javascript:alert(0))">', array('li'));
    $this->assertNoNormalized($f, 'style', t('HTML filter attributes removal -- style, no evasion.'));

    $f = filter_xss('<img onerror   =alert(0)>', array('img'));
    $this->assertNoNormalized($f, 'onerror', t('HTML filter attributes removal evasion -- spaces before equals sign.'));

    $f = filter_xss('<img onabort!#$%&()*~+-_.,:;?@[/|\]^`=alert(0)>', array('img'));
    $this->assertNoNormalized($f, 'onabort', t('HTML filter attributes removal evasion -- non alphanumeric characters before equals sign.'));

    $f = filter_xss('<img oNmediAError=alert(0)>', array('img'));
    $this->assertNoNormalized($f, 'onmediaerror', t('HTML filter attributes removal evasion -- varying case.'));

    // Works at least with IE6.
    $f = filter_xss("<img o\0nfocus\0=alert(0)>", array('img'));
    $this->assertNoNormalized($f, 'focus', t('HTML filter attributes removal evasion -- breaking with nulls.'));

    // Only whitelisted scheme names allowed in attributes.
    $f = filter_xss('<img src="javascript:alert(0)">', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing -- no evasion.'));

    $f = filter_xss('<img src=javascript:alert(0)>', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- no quotes.'));

    // A bit like CVE-2006-0070.
    $f = filter_xss('<img src="javascript:confirm(0)">', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- no alert ;)'));

    $f = filter_xss('<img src=`javascript:alert(0)`>', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- grave accents.'));

    $f = filter_xss('<img dynsrc="javascript:alert(0)">', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing -- rare attribute.'));

    $f = filter_xss('<table background="javascript:alert(0)">', array('table'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing -- another tag.'));

    $f = filter_xss('<base href="javascript:alert(0);//">', array('base'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing -- one more attribute and tag.'));

    $f = filter_xss('<img src="jaVaSCriPt:alert(0)">', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- varying case.'));

    $f = filter_xss('<img src=&#106;&#97;&#118;&#97;&#115;&#99;&#114;&#105;&#112;&#116;&#58;&#97;&#108;&#101;&#114;&#116;&#40;&#48;&#41;>', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- UTF-8 decimal encoding.'));

    $f = filter_xss('<img src=&#00000106&#0000097&#00000118&#0000097&#00000115&#0000099&#00000114&#00000105&#00000112&#00000116&#0000058&#0000097&#00000108&#00000101&#00000114&#00000116&#0000040&#0000048&#0000041>', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- long UTF-8 encoding.'));

    $f = filter_xss('<img src=&#x6A&#x61&#x76&#x61&#x73&#x63&#x72&#x69&#x70&#x74&#x3A&#x61&#x6C&#x65&#x72&#x74&#x28&#x30&#x29>', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- UTF-8 hex encoding.'));

    $f = filter_xss("<img src=\"jav\tascript:alert(0)\">", array('img'));
    $this->assertNoNormalized($f, 'script', t('HTML scheme clearing evasion -- an embedded tab.'));

    $f = filter_xss('<img src="jav&#x09;ascript:alert(0)">', array('img'));
    $this->assertNoNormalized($f, 'script', t('HTML scheme clearing evasion -- an encoded, embedded tab.'));

    $f = filter_xss('<img src="jav&#x000000A;ascript:alert(0)">', array('img'));
    $this->assertNoNormalized($f, 'script', t('HTML scheme clearing evasion -- an encoded, embedded newline.'));

    // With &#xD; this test would fail, but the entity gets turned into
    // &amp;#xD;, so it's OK.
    $f = filter_xss('<img src="jav&#x0D;ascript:alert(0)">', array('img'));
    $this->assertNoNormalized($f, 'script', t('HTML scheme clearing evasion -- an encoded, embedded carriage return.'));

    $f = filter_xss("<img src=\"\n\n\nj\na\nva\ns\ncript:alert(0)\">", array('img'));
    $this->assertNoNormalized($f, 'cript', t('HTML scheme clearing evasion -- broken into many lines.'));

    $f = filter_xss("<img src=\"jav\0a\0\0cript:alert(0)\">", array('img'));
    $this->assertNoNormalized($f, 'cript', t('HTML scheme clearing evasion -- embedded nulls.'));

    $f = filter_xss('<img src=" &#14;  javascript:alert(0)">', array('img'));
    $this->assertNoNormalized($f, 'javascript', t('HTML scheme clearing evasion -- spaces and metacharacters before scheme.'));

    $f = filter_xss('<img src="vbscript:msgbox(0)">', array('img'));
    $this->assertNoNormalized($f, 'vbscript', t('HTML scheme clearing evasion -- another scheme.'));

    $f = filter_xss('<img src="nosuchscheme:notice(0)">', array('img'));
    $this->assertNoNormalized($f, 'nosuchscheme', t('HTML scheme clearing evasion -- unknown scheme.'));

    // Netscape 4.x javascript entities.
    $f = filter_xss('<br size="&{alert(0)}">', array('br'));
    $this->assertNoNormalized($f, 'alert', t('Netscape 4.x javascript entities.'));

    // DRUPAL-SA-2008-006: Invalid UTF-8, these only work as reflected XSS with
    // Internet Explorer 6.
    $f = filter_xss("<p arg=\"\xe0\">\" style=\"background-image: url(javascript:alert(0));\"\xe0<p>", array('p'));
    $this->assertNoNormalized($f, 'style', t('HTML filter -- invalid UTF-8.'));

    $f = filter_xss("\xc0aaa");
    $this->assertEqual($f, '', t('HTML filter -- overlong UTF-8 sequences.'));
  }

  /**
   * Test filter settings, defaults, access restrictions and similar.
   *
   * @todo This is for functions like filter_filter and check_markup, whose
   *   functionality is not completely focused on filtering. Some ideas:
   *   restricting formats according to user permissions, proper cache
   *   handling, defaults -- allowed tags/attributes/protocols.
   *
   * @todo It is possible to add script, iframe etc. to allowed tags, but this
   *   makes HTML filter completely ineffective.
   *
   * @todo Class, id, name and xmlns should be added to disallowed attributes,
   *   or better a whitelist approach should be used for that too.
   */
  function testFilter() {
    // Check that access restriction really works.

    // HTML filter is not able to secure some tags, these should never be
    // allowed.
    $f = filter_filter('process', 0, 'no_such_format', '<script />');
    $this->assertNoNormalized($f, 'script', t('HTML filter should always remove script tags.'));

    $f = filter_filter('process', 0, 'no_such_format', '<iframe />');
    $this->assertNoNormalized($f, 'iframe', t('HTML filter should always remove iframe tags.'));

    $f = filter_filter('process', 0, 'no_such_format', '<object />');
    $this->assertNoNormalized($f, 'object', t('HTML filter should always remove object tags.'));

    $f = filter_filter('process', 0, 'no_such_format', '<style />');
    $this->assertNoNormalized($f, 'style', t('HTML filter should always remove style tags.'));

    // Some tags make CSRF attacks easier, let the user take the risk herself.
    $f = filter_filter('process', 0, 'no_such_format', '<img />');
    $this->assertNoNormalized($f, 'img', t('HTML filter should remove img tags on default.'));

    $f = filter_filter('process', 0, 'no_such_format', '<input />');
    $this->assertNoNormalized($f, 'img', t('HTML filter should remove input tags on default.'));

    // Filtering content of some attributes is infeasible, these shouldn't be
    // allowed too.
    $f = filter_filter('process', 0, 'no_such_format', '<p style="display: none;" />');
    $this->assertNoNormalized($f, 'style', t('HTML filter should remove style attribute on default.'));

    $f = filter_filter('process', 0, 'no_such_format', '<p onerror="alert(0);" />');
    $this->assertNoNormalized($f, 'onerror', t('HTML filter should remove on* attributes on default.'));
  }

  /**
   * Test the spam deterrent.
   */
  function testNoFollowFilter() {
    variable_set('filter_html_nofollow_f', TRUE);

    // Test if the rel="nofollow" attribute is added, even if we try to prevent
    // it.
    $f = _filter_html('<a href="http://www.example.com/">text</a>', 'f');
    $this->assertNormalized($f, 'rel="nofollow"', t('Spam deterrent -- no evasion.'));

    $f = _filter_html('<A href="http://www.example.com/">text</a>', 'f');
    $this->assertNormalized($f, 'rel="nofollow"', t('Spam deterrent evasion -- capital A.'));

    $f = _filter_html("<a/href=\"http://www.example.com/\">text</a>", 'f');
    $this->assertNormalized($f, 'rel="nofollow"', t('Spam deterrent evasion -- non whitespace character after tag name.'));

    $f = _filter_html("<\0a\0 href=\"http://www.example.com/\">text</a>", 'f');
    $this->assertNormalized($f, 'rel="nofollow"', t('Spam deterrent evasion -- some nulls.'));

    $f = _filter_html('<!--[if true]><a href="http://www.example.com/">text</a><![endif]-->', 'f');
    $this->assertNormalized($f, 'rel="nofollow"', t('Spam deterrent evasion -- link within a comment.'));
  }

  /**
   * Test the loose, admin HTML filter.
   */
  function testAdminHtmlFilter() {
    // DRUPAL-SA-2008-044
    $f = filter_xss_admin('<object />');
    $this->assertNoNormalized($f, 'object', t('Admin HTML filter -- should not allow object tag.'));

    $f = filter_xss_admin('<script />');
    $this->assertNoNormalized($f, 'script', t('Admin HTML filter -- should not allow script tag.'));

    $f = filter_xss_admin('<style /><iframe /><frame /><frameset /><meta /><link /><embed /><applet /><param /><layer />');
    $this->assertEqual($f, '', t('Admin HTML filter -- should never allow some tags.'));
  }

  /**
   * Test the HTML escaping filter.
   *
   * Here we test only whether check_plain() does what it should.
   */
  function testNoHtmlFilter() {
    // Test that characters that have special meaning in XML are changed into
    // entities.
    $f = check_plain('<>&"');
    $this->assertEqual($f, '&lt;&gt;&amp;&quot;', t('No HTML filter basic test.'));

    // A single quote can also be used for evil things in some contexts.
    $f = check_plain('\'');
    $this->assertEqual($f, '&#039;', t('No HTML filter -- single quote.'));

    // Test that the filter is not fooled by different evasion techniques.
    $f = check_plain("\xc2\"");
    $this->assertEqual($f, '', t('No HTML filter -- invalid UTF-8.'));
  }

  /**
   * Test the URL filter.
   */
  function testUrlFilter() {
    variable_set('filter_url_length_f', 496);

    // Converting URLs.
    $f = _filter_url('http://www.example.com/', 'f');
    $this->assertEqual($f, '<a href="http://www.example.com/" title="http://www.example.com/">http://www.example.com/</a>', t('Converting URLs.'));

    $f = _filter_url('http://www.example.com/?a=1&b=2', 'f');
    $this->assertEqual($f, '<a href="http://www.example.com/?a=1&amp;b=2" title="http://www.example.com/?a=1&amp;b=2">http://www.example.com/?a=1&amp;b=2</a>', t('Converting URLs -- ampersands.'));

    $f = _filter_url('ftp://user:pass@ftp.example.com/dir1/dir2', 'f');
    $this->assertEqual($f, '<a href="ftp://user:pass@ftp.example.com/dir1/dir2" title="ftp://user:pass@ftp.example.com/dir1/dir2">ftp://user:pass@ftp.example.com/dir1/dir2</a>', t('Converting URLs -- FTP scheme.'));

    // Converting domain names.
    $f = _filter_url('www.example.com', 'f');
    $this->assertEqual($f, '<a href="http://www.example.com" title="www.example.com">www.example.com</a>', t('Converting domain names.'));

    $f = _filter_url('<li>www.example.com</li>', 'f');
    $this->assertEqual($f, '<li><a href="http://www.example.com" title="www.example.com">www.example.com</a></li>', t('Converting domain names -- domain in a list.'));

    $f = _filter_url('(www.example.com/dir?a=1&b=2#a)', 'f');
    $this->assertEqual($f, '(<a href="http://www.example.com/dir?a=1&amp;b=2#a" title="www.example.com/dir?a=1&amp;b=2#a">www.example.com/dir?a=1&amp;b=2#a</a>)', t('Converting domain names --  domain in parentheses.'));

    // Converting e-mail addresses.
    $f = _filter_url('johndoe@example.com', 'f');
    $this->assertEqual($f, '<a href="mailto:johndoe@example.com">johndoe@example.com</a>', t('Converting e-mail addresses.'));

    $f = _filter_url('aaa@sub.tv', 'f');
    $this->assertEqual($f, '<a href="mailto:aaa@sub.tv">aaa@sub.tv</a>', t('Converting e-mail addresses -- a short e-mail from Tuvalu.'));

    // URL trimming.
    variable_set('filter_url_length_f', 28);

    $f = _filter_url('http://www.example.com/d/ff.ext?a=1&b=2#a1', 'f');
    $this->assertNormalized($f, 'http://www.example.com/d/ff....', t('URL trimming.'));

    // Not breaking existing links.
    $f = _filter_url('<a href="http://www.example.com">www.example.com</a>', 'f');
    $this->assertEqual($f, '<a href="http://www.example.com">www.example.com</a>', t('Converting URLs -- do not break existing links.'));

    $f = _filter_url('<a href="foo">http://www.example.com</a>', 'f');
    $this->assertEqual($f, '<a href="foo">http://www.example.com</a>', t('Converting URLs -- do not break existing, relative links.'));

    // Addresses within some tags such as code or script should not be converted.
    $f = _filter_url('<code>http://www.example.com</code>', 'f');
    $this->assertEqual($f, '<code>http://www.example.com</code>', t('Converting URLs -- skip code contents.'));

    $f = _filter_url('<code><em>http://www.example.com</em></code>', 'f');
    $this->assertEqual($f, '<code><em>http://www.example.com</em></code>', t('Converting URLs -- really skip code contents.'));

    $f = _filter_url('<script>http://www.example.com</script>', 'f');
    $this->assertEqual($f, '<script>http://www.example.com</script>', t('Converting URLs -- do not process scripts.'));

    // Addresses in attributes should not be converted.
    $f = _filter_url('<p xmlns="http://www.example.com" />', 'f');
    $this->assertEqual($f, '<p xmlns="http://www.example.com" />', t('Converting URLs -- do not convert addresses in attributes.'));

    $f = _filter_url('<a title="Go to www.example.com" href="http://www.example.com">text</a>', 'f');
    $this->assertEqual($f, '<a title="Go to www.example.com" href="http://www.example.com">text</a>', t('Converting URLs -- do not break existing links with custom title attribute.'));

    // Even though a dot at the end of a URL can indicate a fully qualified
    // domain name, such usage is rare compared to using a link at the end
    // of a sentence, so remove the dot from the link.
    // @todo It can also be used at the end of a filename or a query string.
    $f = _filter_url('www.example.com.', 'f');
    $this->assertEqual($f, '<a href="http://www.example.com" title="www.example.com">www.example.com</a>.', t('Converting URLs -- do not recognize a dot at the end of a domain name (FQDNs).'));

    $f = _filter_url('http://www.example.com.', 'f');
    $this->assertEqual($f, '<a href="http://www.example.com" title="http://www.example.com">http://www.example.com</a>.', t('Converting URLs -- do not recognize a dot at the end of an URL (FQDNs).'));

    $f = _filter_url('www.example.com/index.php?a=.', 'f');
    $this->assertEqual($f, '<a href="http://www.example.com/index.php?a=" title="www.example.com/index.php?a=">www.example.com/index.php?a=</a>.', t('Converting URLs -- do forget about a dot at the end of a query string.'));
  }

  /**
   * Test the HTML corrector.
   *
   * @todo This test could really use some validity checking function.
   */
  function testHtmlCorrector() {
    // Tag closing.
    $f = _filter_htmlcorrector('<p>text');
    $this->assertEqual($f, '<p>text</p>', t('HTML corrector -- tag closing at the end of input.'));

    $f = _filter_htmlcorrector('<p>text<p><p>text');
    $this->assertEqual($f, '<p>text</p><p></p><p>text</p>', t('HTML corrector -- tag closing.'));

    $f = _filter_htmlcorrector("<ul><li>e1<li>e2");
    $this->assertEqual($f, "<ul><li>e1</li><li>e2</li></ul>", t('HTML corrector -- unclosed list tags.'));

    $f = _filter_htmlcorrector('<div id="d">content');
    $this->assertEqual($f, '<div id="d">content</div>', t('HTML corrector -- unclosed tag with attribute.'));

    // XHTML slash for empty elements.
    $f = _filter_htmlcorrector('<hr><br>');
    $this->assertEqual($f, '<hr /><br />', t('HTML corrector -- XHTML closing slash.'));
  }

  function createFormat($filter) {
    $edit = array(
      'name' => $this->randomName(),
      'roles[2]' => TRUE,
      'filters[filter/' . $filter . ']' => TRUE,
    );
    $this->drupalPost('admin/settings/filter/add', $edit, t('Save configuration'));
    return db_query("SELECT * FROM {filter_format} WHERE name = :name", array(':name' => $edit['name']))->fetchObject();
  }

  function deleteFormat($format) {
    if ($format !== NULL) {
      $this->drupalPost('admin/settings/formats/delete/' . $format->format, array(), t('Delete'));
    }
  }

  /**
   * Asserts that a text transformed to lowercase with HTML entities decoded does contains a given string.
   *
   * Otherwise fails the test with a given message, similar to all the
   * SimpleTest assert* functions.
   *
   * Note that this does not remove nulls, new lines and other characters that
   * could be used to obscure a tag or an attribute name.
   *
   * @param $haystack
   *   Text to look in.
   * @param $needle
   *   Lowercase, plain text to look for.
   * @param $message
   *   Message to display if failed.
   * @param $group
   *   The group this message belongs to, defaults to 'Other'.
   * @return
   *   TRUE on pass, FALSE on fail.
   */
  function assertNormalized($haystack, $needle, $message = '', $group = 'Other') {
    return $this->assertTrue(strpos(strtolower(decode_entities($haystack)), $needle) !== FALSE, $message, $group);
  }

  /**
   * Asserts that text transformed to lowercase with HTML entities decoded does not contain a given string.
   *
   * Otherwise fails the test with a given message, similar to all the
   * SimpleTest assert* functions.
   *
   * Note that this does not remove nulls, new lines, and other character that
   * could be used to obscure a tag or an attribute name.
   *
   * @param $haystack
   *   Text to look in.
   * @param $needle
   *   Lowercase, plain text to look for.
   * @param $message
   *   Message to display if failed.
   * @param $group
   *   The group this message belongs to, defaults to 'Other'.
   * @return
   *   TRUE on pass, FALSE on fail.
   */
  function assertNoNormalized($haystack, $needle, $message = '', $group = 'Other') {
    return $this->assertTrue(strpos(strtolower(decode_entities($haystack)), $needle) === FALSE, $message, $group);
  }
}