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moberley committed 6e09a74

Import PageDown.

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PAGEDOWN-LICENSE.txt

+A javascript port of Markdown, as used on Stack Overflow
+and the rest of Stack Exchange network.
+
+Largely based on showdown.js by John Fraser (Attacklab).
+
+Original Markdown Copyright (c) 2004-2005 John Gruber
+  <http://daringfireball.net/projects/markdown/>
+
+
+Original Showdown code copyright (c) 2007 John Fraser
+
+Modifications and bugfixes (c) 2009 Dana Robinson
+Modifications and bugfixes (c) 2009-2011 Stack Exchange Inc.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+

pagedown/static/pagedown/Markdown.Converter.js

+var Markdown;
+
+if (typeof exports === "object" && typeof require === "function") // we're in a CommonJS (e.g. Node.js) module
+    Markdown = exports;
+else
+    Markdown = {};
+    
+// The following text is included for historical reasons, but should
+// be taken with a pinch of salt; it's not all true anymore.
+
+//
+// Wherever possible, Showdown is a straight, line-by-line port
+// of the Perl version of Markdown.
+//
+// This is not a normal parser design; it's basically just a
+// series of string substitutions.  It's hard to read and
+// maintain this way,  but keeping Showdown close to the original
+// design makes it easier to port new features.
+//
+// More importantly, Showdown behaves like markdown.pl in most
+// edge cases.  So web applications can do client-side preview
+// in Javascript, and then build identical HTML on the server.
+//
+// This port needs the new RegExp functionality of ECMA 262,
+// 3rd Edition (i.e. Javascript 1.5).  Most modern web browsers
+// should do fine.  Even with the new regular expression features,
+// We do a lot of work to emulate Perl's regex functionality.
+// The tricky changes in this file mostly have the "attacklab:"
+// label.  Major or self-explanatory changes don't.
+//
+// Smart diff tools like Araxis Merge will be able to match up
+// this file with markdown.pl in a useful way.  A little tweaking
+// helps: in a copy of markdown.pl, replace "#" with "//" and
+// replace "$text" with "text".  Be sure to ignore whitespace
+// and line endings.
+//
+
+
+//
+// Usage:
+//
+//   var text = "Markdown *rocks*.";
+//
+//   var converter = new Markdown.Converter();
+//   var html = converter.makeHtml(text);
+//
+//   alert(html);
+//
+// Note: move the sample code to the bottom of this
+// file before uncommenting it.
+//
+
+(function () {
+
+    function identity(x) { return x; }
+    function returnFalse(x) { return false; }
+
+    function HookCollection() { }
+
+    HookCollection.prototype = {
+
+        chain: function (hookname, func) {
+            var original = this[hookname];
+            if (!original)
+                throw new Error("unknown hook " + hookname);
+
+            if (original === identity)
+                this[hookname] = func;
+            else
+                this[hookname] = function (x) { return func(original(x)); }
+        },
+        set: function (hookname, func) {
+            if (!this[hookname])
+                throw new Error("unknown hook " + hookname);
+            this[hookname] = func;
+        },
+        addNoop: function (hookname) {
+            this[hookname] = identity;
+        },
+        addFalse: function (hookname) {
+            this[hookname] = returnFalse;
+        }
+    };
+
+    Markdown.HookCollection = HookCollection;
+
+    // g_urls and g_titles allow arbitrary user-entered strings as keys. This
+    // caused an exception (and hence stopped the rendering) when the user entered
+    // e.g. [push] or [__proto__]. Adding a prefix to the actual key prevents this
+    // (since no builtin property starts with "s_"). See
+    // http://meta.stackoverflow.com/questions/64655/strange-wmd-bug
+    // (granted, switching from Array() to Object() alone would have left only __proto__
+    // to be a problem)
+    function SaveHash() { }
+    SaveHash.prototype = {
+        set: function (key, value) {
+            this["s_" + key] = value;
+        },
+        get: function (key) {
+            return this["s_" + key];
+        }
+    };
+
+    Markdown.Converter = function () {
+        var pluginHooks = this.hooks = new HookCollection();
+        pluginHooks.addNoop("plainLinkText");  // given a URL that was encountered by itself (without markup), should return the link text that's to be given to this link
+        pluginHooks.addNoop("preConversion");  // called with the orignal text as given to makeHtml. The result of this plugin hook is the actual markdown source that will be cooked
+        pluginHooks.addNoop("postConversion"); // called with the final cooked HTML code. The result of this plugin hook is the actual output of makeHtml
+
+        //
+        // Private state of the converter instance:
+        //
+
+        // Global hashes, used by various utility routines
+        var g_urls;
+        var g_titles;
+        var g_html_blocks;
+
+        // Used to track when we're inside an ordered or unordered list
+        // (see _ProcessListItems() for details):
+        var g_list_level;
+
+        this.makeHtml = function (text) {
+
+            //
+            // Main function. The order in which other subs are called here is
+            // essential. Link and image substitutions need to happen before
+            // _EscapeSpecialCharsWithinTagAttributes(), so that any *'s or _'s in the <a>
+            // and <img> tags get encoded.
+            //
+
+            // This will only happen if makeHtml on the same converter instance is called from a plugin hook.
+            // Don't do that.
+            if (g_urls)
+                throw new Error("Recursive call to converter.makeHtml");
+        
+            // Create the private state objects.
+            g_urls = new SaveHash();
+            g_titles = new SaveHash();
+            g_html_blocks = [];
+            g_list_level = 0;
+
+            text = pluginHooks.preConversion(text);
+
+            // attacklab: Replace ~ with ~T
+            // This lets us use tilde as an escape char to avoid md5 hashes
+            // The choice of character is arbitray; anything that isn't
+            // magic in Markdown will work.
+            text = text.replace(/~/g, "~T");
+
+            // attacklab: Replace $ with ~D
+            // RegExp interprets $ as a special character
+            // when it's in a replacement string
+            text = text.replace(/\$/g, "~D");
+
+            // Standardize line endings
+            text = text.replace(/\r\n/g, "\n"); // DOS to Unix
+            text = text.replace(/\r/g, "\n"); // Mac to Unix
+
+            // Make sure text begins and ends with a couple of newlines:
+            text = "\n\n" + text + "\n\n";
+
+            // Convert all tabs to spaces.
+            text = _Detab(text);
+
+            // Strip any lines consisting only of spaces and tabs.
+            // This makes subsequent regexen easier to write, because we can
+            // match consecutive blank lines with /\n+/ instead of something
+            // contorted like /[ \t]*\n+/ .
+            text = text.replace(/^[ \t]+$/mg, "");
+
+            // Turn block-level HTML blocks into hash entries
+            text = _HashHTMLBlocks(text);
+
+            // Strip link definitions, store in hashes.
+            text = _StripLinkDefinitions(text);
+
+            text = _RunBlockGamut(text);
+
+            text = _UnescapeSpecialChars(text);
+
+            // attacklab: Restore dollar signs
+            text = text.replace(/~D/g, "$$");
+
+            // attacklab: Restore tildes
+            text = text.replace(/~T/g, "~");
+
+            text = pluginHooks.postConversion(text);
+
+            g_html_blocks = g_titles = g_urls = null;
+
+            return text;
+        };
+
+        function _StripLinkDefinitions(text) {
+            //
+            // Strips link definitions from text, stores the URLs and titles in
+            // hash references.
+            //
+
+            // Link defs are in the form: ^[id]: url "optional title"
+
+            /*
+            text = text.replace(/
+                ^[ ]{0,3}\[(.+)\]:  // id = $1  attacklab: g_tab_width - 1
+                [ \t]*
+                \n?                 // maybe *one* newline
+                [ \t]*
+                <?(\S+?)>?          // url = $2
+                (?=\s|$)            // lookahead for whitespace instead of the lookbehind removed below
+                [ \t]*
+                \n?                 // maybe one newline
+                [ \t]*
+                (                   // (potential) title = $3
+                    (\n*)           // any lines skipped = $4 attacklab: lookbehind removed
+                    [ \t]+
+                    ["(]
+                    (.+?)           // title = $5
+                    [")]
+                    [ \t]*
+                )?                  // title is optional
+                (?:\n+|$)
+            /gm, function(){...});
+            */
+
+            text = text.replace(/^[ ]{0,3}\[(.+)\]:[ \t]*\n?[ \t]*<?(\S+?)>?(?=\s|$)[ \t]*\n?[ \t]*((\n*)["(](.+?)[")][ \t]*)?(?:\n+)/gm,
+                function (wholeMatch, m1, m2, m3, m4, m5) {
+                    m1 = m1.toLowerCase();
+                    g_urls.set(m1, _EncodeAmpsAndAngles(m2));  // Link IDs are case-insensitive
+                    if (m4) {
+                        // Oops, found blank lines, so it's not a title.
+                        // Put back the parenthetical statement we stole.
+                        return m3;
+                    } else if (m5) {
+                        g_titles.set(m1, m5.replace(/"/g, "&quot;"));
+                    }
+
+                    // Completely remove the definition from the text
+                    return "";
+                }
+            );
+
+            return text;
+        }
+
+        function _HashHTMLBlocks(text) {
+
+            // Hashify HTML blocks:
+            // We only want to do this for block-level HTML tags, such as headers,
+            // lists, and tables. That's because we still want to wrap <p>s around
+            // "paragraphs" that are wrapped in non-block-level tags, such as anchors,
+            // phrase emphasis, and spans. The list of tags we're looking for is
+            // hard-coded:
+            var block_tags_a = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del"
+            var block_tags_b = "p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math"
+
+            // First, look for nested blocks, e.g.:
+            //   <div>
+            //     <div>
+            //     tags for inner block must be indented.
+            //     </div>
+            //   </div>
+            //
+            // The outermost tags must start at the left margin for this to match, and
+            // the inner nested divs must be indented.
+            // We need to do this before the next, more liberal match, because the next
+            // match will start at the first `<div>` and stop at the first `</div>`.
+
+            // attacklab: This regex can be expensive when it fails.
+
+            /*
+            text = text.replace(/
+                (                       // save in $1
+                    ^                   // start of line  (with /m)
+                    <($block_tags_a)    // start tag = $2
+                    \b                  // word break
+                                        // attacklab: hack around khtml/pcre bug...
+                    [^\r]*?\n           // any number of lines, minimally matching
+                    </\2>               // the matching end tag
+                    [ \t]*              // trailing spaces/tabs
+                    (?=\n+)             // followed by a newline
+                )                       // attacklab: there are sentinel newlines at end of document
+            /gm,function(){...}};
+            */
+            text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math|ins|del)\b[^\r]*?\n<\/\2>[ \t]*(?=\n+))/gm, hashElement);
+
+            //
+            // Now match more liberally, simply from `\n<tag>` to `</tag>\n`
+            //
+
+            /*
+            text = text.replace(/
+                (                       // save in $1
+                    ^                   // start of line  (with /m)
+                    <($block_tags_b)    // start tag = $2
+                    \b                  // word break
+                                        // attacklab: hack around khtml/pcre bug...
+                    [^\r]*?             // any number of lines, minimally matching
+                    .*</\2>             // the matching end tag
+                    [ \t]*              // trailing spaces/tabs
+                    (?=\n+)             // followed by a newline
+                )                       // attacklab: there are sentinel newlines at end of document
+            /gm,function(){...}};
+            */
+            text = text.replace(/^(<(p|div|h[1-6]|blockquote|pre|table|dl|ol|ul|script|noscript|form|fieldset|iframe|math)\b[^\r]*?.*<\/\2>[ \t]*(?=\n+)\n)/gm, hashElement);
+
+            // Special case just for <hr />. It was easier to make a special case than
+            // to make the other regex more complicated.  
+
+            /*
+            text = text.replace(/
+                \n                  // Starting after a blank line
+                [ ]{0,3}
+                (                   // save in $1
+                    (<(hr)          // start tag = $2
+                        \b          // word break
+                        ([^<>])*?
+                    \/?>)           // the matching end tag
+                    [ \t]*
+                    (?=\n{2,})      // followed by a blank line
+                )
+            /g,hashElement);
+            */
+            text = text.replace(/\n[ ]{0,3}((<(hr)\b([^<>])*?\/?>)[ \t]*(?=\n{2,}))/g, hashElement);
+
+            // Special case for standalone HTML comments:
+
+            /*
+            text = text.replace(/
+                \n\n                                            // Starting after a blank line
+                [ ]{0,3}                                        // attacklab: g_tab_width - 1
+                (                                               // save in $1
+                    <!
+                    (--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)   // see http://www.w3.org/TR/html-markup/syntax.html#comments and http://meta.stackoverflow.com/q/95256
+                    >
+                    [ \t]*
+                    (?=\n{2,})                                  // followed by a blank line
+                )
+            /g,hashElement);
+            */
+            text = text.replace(/\n\n[ ]{0,3}(<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>[ \t]*(?=\n{2,}))/g, hashElement);
+
+            // PHP and ASP-style processor instructions (<?...?> and <%...%>)
+
+            /*
+            text = text.replace(/
+                (?:
+                    \n\n            // Starting after a blank line
+                )
+                (                   // save in $1
+                    [ ]{0,3}        // attacklab: g_tab_width - 1
+                    (?:
+                        <([?%])     // $2
+                        [^\r]*?
+                        \2>
+                    )
+                    [ \t]*
+                    (?=\n{2,})      // followed by a blank line
+                )
+            /g,hashElement);
+            */
+            text = text.replace(/(?:\n\n)([ ]{0,3}(?:<([?%])[^\r]*?\2>)[ \t]*(?=\n{2,}))/g, hashElement);
+
+            return text;
+        }
+
+        function hashElement(wholeMatch, m1) {
+            var blockText = m1;
+
+            // Undo double lines
+            blockText = blockText.replace(/^\n+/, "");
+
+            // strip trailing blank lines
+            blockText = blockText.replace(/\n+$/g, "");
+
+            // Replace the element text with a marker ("~KxK" where x is its key)
+            blockText = "\n\n~K" + (g_html_blocks.push(blockText) - 1) + "K\n\n";
+
+            return blockText;
+        }
+
+        function _RunBlockGamut(text, doNotUnhash) {
+            //
+            // These are all the transformations that form block-level
+            // tags like paragraphs, headers, and list items.
+            //
+            text = _DoHeaders(text);
+
+            // Do Horizontal Rules:
+            var replacement = "<hr />\n";
+            text = text.replace(/^[ ]{0,2}([ ]?\*[ ]?){3,}[ \t]*$/gm, replacement);
+            text = text.replace(/^[ ]{0,2}([ ]?-[ ]?){3,}[ \t]*$/gm, replacement);
+            text = text.replace(/^[ ]{0,2}([ ]?_[ ]?){3,}[ \t]*$/gm, replacement);
+
+            text = _DoLists(text);
+            text = _DoCodeBlocks(text);
+            text = _DoBlockQuotes(text);
+
+            // We already ran _HashHTMLBlocks() before, in Markdown(), but that
+            // was to escape raw HTML in the original Markdown source. This time,
+            // we're escaping the markup we've just created, so that we don't wrap
+            // <p> tags around block-level tags.
+            text = _HashHTMLBlocks(text);
+            text = _FormParagraphs(text, doNotUnhash);
+
+            return text;
+        }
+
+        function _RunSpanGamut(text) {
+            //
+            // These are all the transformations that occur *within* block-level
+            // tags like paragraphs, headers, and list items.
+            //
+
+            text = _DoCodeSpans(text);
+            text = _EscapeSpecialCharsWithinTagAttributes(text);
+            text = _EncodeBackslashEscapes(text);
+
+            // Process anchor and image tags. Images must come first,
+            // because ![foo][f] looks like an anchor.
+            text = _DoImages(text);
+            text = _DoAnchors(text);
+
+            // Make links out of things like `<http://example.com/>`
+            // Must come after _DoAnchors(), because you can use < and >
+            // delimiters in inline links like [this](<url>).
+            text = _DoAutoLinks(text);
+            
+            text = text.replace(/~P/g, "://"); // put in place to prevent autolinking; reset now
+            
+            text = _EncodeAmpsAndAngles(text);
+            text = _DoItalicsAndBold(text);
+
+            // Do hard breaks:
+            text = text.replace(/  +\n/g, " <br>\n");
+
+            return text;
+        }
+
+        function _EscapeSpecialCharsWithinTagAttributes(text) {
+            //
+            // Within tags -- meaning between < and > -- encode [\ ` * _] so they
+            // don't conflict with their use in Markdown for code, italics and strong.
+            //
+
+            // Build a regex to find HTML tags and comments.  See Friedl's 
+            // "Mastering Regular Expressions", 2nd Ed., pp. 200-201.
+
+            // SE: changed the comment part of the regex
+
+            var regex = /(<[a-z\/!$]("[^"]*"|'[^']*'|[^'">])*>|<!(--(?:|(?:[^>-]|-[^>])(?:[^-]|-[^-])*)--)>)/gi;
+
+            text = text.replace(regex, function (wholeMatch) {
+                var tag = wholeMatch.replace(/(.)<\/?code>(?=.)/g, "$1`");
+                tag = escapeCharacters(tag, wholeMatch.charAt(1) == "!" ? "\\`*_/" : "\\`*_"); // also escape slashes in comments to prevent autolinking there -- http://meta.stackoverflow.com/questions/95987
+                return tag;
+            });
+
+            return text;
+        }
+
+        function _DoAnchors(text) {
+            //
+            // Turn Markdown link shortcuts into XHTML <a> tags.
+            //
+            //
+            // First, handle reference-style links: [link text] [id]
+            //
+
+            /*
+            text = text.replace(/
+                (                           // wrap whole match in $1
+                    \[
+                    (
+                        (?:
+                            \[[^\]]*\]      // allow brackets nested one level
+                            |
+                            [^\[]           // or anything else
+                        )*
+                    )
+                    \]
+
+                    [ ]?                    // one optional space
+                    (?:\n[ ]*)?             // one optional newline followed by spaces
+
+                    \[
+                    (.*?)                   // id = $3
+                    \]
+                )
+                ()()()()                    // pad remaining backreferences
+            /g, writeAnchorTag);
+            */
+            text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeAnchorTag);
+
+            //
+            // Next, inline-style links: [link text](url "optional title")
+            //
+
+            /*
+            text = text.replace(/
+                (                           // wrap whole match in $1
+                    \[
+                    (
+                        (?:
+                            \[[^\]]*\]      // allow brackets nested one level
+                            |
+                            [^\[\]]         // or anything else
+                        )*
+                    )
+                    \]
+                    \(                      // literal paren
+                    [ \t]*
+                    ()                      // no id, so leave $3 empty
+                    <?(                     // href = $4
+                        (?:
+                            \([^)]*\)       // allow one level of (correctly nested) parens (think MSDN)
+                            |
+                            [^()]
+                        )*?
+                    )>?                
+                    [ \t]*
+                    (                       // $5
+                        (['"])              // quote char = $6
+                        (.*?)               // Title = $7
+                        \6                  // matching quote
+                        [ \t]*              // ignore any spaces/tabs between closing quote and )
+                    )?                      // title is optional
+                    \)
+                )
+            /g, writeAnchorTag);
+            */
+
+            text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\]\([ \t]*()<?((?:\([^)]*\)|[^()])*?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeAnchorTag);
+
+            //
+            // Last, handle reference-style shortcuts: [link text]
+            // These must come last in case you've also got [link test][1]
+            // or [link test](/foo)
+            //
+
+            /*
+            text = text.replace(/
+                (                   // wrap whole match in $1
+                    \[
+                    ([^\[\]]+)      // link text = $2; can't contain '[' or ']'
+                    \]
+                )
+                ()()()()()          // pad rest of backreferences
+            /g, writeAnchorTag);
+            */
+            text = text.replace(/(\[([^\[\]]+)\])()()()()()/g, writeAnchorTag);
+
+            return text;
+        }
+
+        function writeAnchorTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
+            if (m7 == undefined) m7 = "";
+            var whole_match = m1;
+            var link_text = m2.replace(/:\/\//g, "~P"); // to prevent auto-linking withing the link. will be converted back after the auto-linker runs
+            var link_id = m3.toLowerCase();
+            var url = m4;
+            var title = m7;
+
+            if (url == "") {
+                if (link_id == "") {
+                    // lower-case and turn embedded newlines into spaces
+                    link_id = link_text.toLowerCase().replace(/ ?\n/g, " ");
+                }
+                url = "#" + link_id;
+
+                if (g_urls.get(link_id) != undefined) {
+                    url = g_urls.get(link_id);
+                    if (g_titles.get(link_id) != undefined) {
+                        title = g_titles.get(link_id);
+                    }
+                }
+                else {
+                    if (whole_match.search(/\(\s*\)$/m) > -1) {
+                        // Special case for explicit empty url
+                        url = "";
+                    } else {
+                        return whole_match;
+                    }
+                }
+            }
+            url = encodeProblemUrlChars(url);
+            url = escapeCharacters(url, "*_");
+            var result = "<a href=\"" + url + "\"";
+
+            if (title != "") {
+                title = attributeEncode(title);
+                title = escapeCharacters(title, "*_");
+                result += " title=\"" + title + "\"";
+            }
+
+            result += ">" + link_text + "</a>";
+
+            return result;
+        }
+
+        function _DoImages(text) {
+            //
+            // Turn Markdown image shortcuts into <img> tags.
+            //
+
+            //
+            // First, handle reference-style labeled images: ![alt text][id]
+            //
+
+            /*
+            text = text.replace(/
+                (                   // wrap whole match in $1
+                    !\[
+                    (.*?)           // alt text = $2
+                    \]
+
+                    [ ]?            // one optional space
+                    (?:\n[ ]*)?     // one optional newline followed by spaces
+
+                    \[
+                    (.*?)           // id = $3
+                    \]
+                )
+                ()()()()            // pad rest of backreferences
+            /g, writeImageTag);
+            */
+            text = text.replace(/(!\[(.*?)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeImageTag);
+
+            //
+            // Next, handle inline images:  ![alt text](url "optional title")
+            // Don't forget: encode * and _
+
+            /*
+            text = text.replace(/
+                (                   // wrap whole match in $1
+                    !\[
+                    (.*?)           // alt text = $2
+                    \]
+                    \s?             // One optional whitespace character
+                    \(              // literal paren
+                    [ \t]*
+                    ()              // no id, so leave $3 empty
+                    <?(\S+?)>?      // src url = $4
+                    [ \t]*
+                    (               // $5
+                        (['"])      // quote char = $6
+                        (.*?)       // title = $7
+                        \6          // matching quote
+                        [ \t]*
+                    )?              // title is optional
+                    \)
+                )
+            /g, writeImageTag);
+            */
+            text = text.replace(/(!\[(.*?)\]\s?\([ \t]*()<?(\S+?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeImageTag);
+
+            return text;
+        }
+        
+        function attributeEncode(text) {
+            // unconditionally replace angle brackets here -- what ends up in an attribute (e.g. alt or title)
+            // never makes sense to have verbatim HTML in it (and the sanitizer would totally break it)
+            return text.replace(/>/g, "&gt;").replace(/</g, "&lt;").replace(/"/g, "&quot;");
+        }
+
+        function writeImageTag(wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
+            var whole_match = m1;
+            var alt_text = m2;
+            var link_id = m3.toLowerCase();
+            var url = m4;
+            var title = m7;
+
+            if (!title) title = "";
+
+            if (url == "") {
+                if (link_id == "") {
+                    // lower-case and turn embedded newlines into spaces
+                    link_id = alt_text.toLowerCase().replace(/ ?\n/g, " ");
+                }
+                url = "#" + link_id;
+
+                if (g_urls.get(link_id) != undefined) {
+                    url = g_urls.get(link_id);
+                    if (g_titles.get(link_id) != undefined) {
+                        title = g_titles.get(link_id);
+                    }
+                }
+                else {
+                    return whole_match;
+                }
+            }
+            
+            alt_text = escapeCharacters(attributeEncode(alt_text), "*_[]()");
+            url = escapeCharacters(url, "*_");
+            var result = "<img src=\"" + url + "\" alt=\"" + alt_text + "\"";
+
+            // attacklab: Markdown.pl adds empty title attributes to images.
+            // Replicate this bug.
+
+            //if (title != "") {
+            title = attributeEncode(title);
+            title = escapeCharacters(title, "*_");
+            result += " title=\"" + title + "\"";
+            //}
+
+            result += " />";
+
+            return result;
+        }
+
+        function _DoHeaders(text) {
+
+            // Setext-style headers:
+            //  Header 1
+            //  ========
+            //  
+            //  Header 2
+            //  --------
+            //
+            text = text.replace(/^(.+)[ \t]*\n=+[ \t]*\n+/gm,
+                function (wholeMatch, m1) { return "<h1>" + _RunSpanGamut(m1) + "</h1>\n\n"; }
+            );
+
+            text = text.replace(/^(.+)[ \t]*\n-+[ \t]*\n+/gm,
+                function (matchFound, m1) { return "<h2>" + _RunSpanGamut(m1) + "</h2>\n\n"; }
+            );
+
+            // atx-style headers:
+            //  # Header 1
+            //  ## Header 2
+            //  ## Header 2 with closing hashes ##
+            //  ...
+            //  ###### Header 6
+            //
+
+            /*
+            text = text.replace(/
+                ^(\#{1,6})      // $1 = string of #'s
+                [ \t]*
+                (.+?)           // $2 = Header text
+                [ \t]*
+                \#*             // optional closing #'s (not counted)
+                \n+
+            /gm, function() {...});
+            */
+
+            text = text.replace(/^(\#{1,6})[ \t]*(.+?)[ \t]*\#*\n+/gm,
+                function (wholeMatch, m1, m2) {
+                    var h_level = m1.length;
+                    return "<h" + h_level + ">" + _RunSpanGamut(m2) + "</h" + h_level + ">\n\n";
+                }
+            );
+
+            return text;
+        }
+
+        function _DoLists(text) {
+            //
+            // Form HTML ordered (numbered) and unordered (bulleted) lists.
+            //
+
+            // attacklab: add sentinel to hack around khtml/safari bug:
+            // http://bugs.webkit.org/show_bug.cgi?id=11231
+            text += "~0";
+
+            // Re-usable pattern to match any entirel ul or ol list:
+
+            /*
+            var whole_list = /
+                (                                   // $1 = whole list
+                    (                               // $2
+                        [ ]{0,3}                    // attacklab: g_tab_width - 1
+                        ([*+-]|\d+[.])              // $3 = first list item marker
+                        [ \t]+
+                    )
+                    [^\r]+?
+                    (                               // $4
+                        ~0                          // sentinel for workaround; should be $
+                        |
+                        \n{2,}
+                        (?=\S)
+                        (?!                         // Negative lookahead for another list item marker
+                            [ \t]*
+                            (?:[*+-]|\d+[.])[ \t]+
+                        )
+                    )
+                )
+            /g
+            */
+            var whole_list = /^(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/gm;
+
+            if (g_list_level) {
+                text = text.replace(whole_list, function (wholeMatch, m1, m2) {
+                    var list = m1;
+                    var list_type = (m2.search(/[*+-]/g) > -1) ? "ul" : "ol";
+
+                    var result = _ProcessListItems(list, list_type);
+
+                    // Trim any trailing whitespace, to put the closing `</$list_type>`
+                    // up on the preceding line, to get it past the current stupid
+                    // HTML block parser. This is a hack to work around the terrible
+                    // hack that is the HTML block parser.
+                    result = result.replace(/\s+$/, "");
+                    result = "<" + list_type + ">" + result + "</" + list_type + ">\n";
+                    return result;
+                });
+            } else {
+                whole_list = /(\n\n|^\n?)(([ ]{0,3}([*+-]|\d+[.])[ \t]+)[^\r]+?(~0|\n{2,}(?=\S)(?![ \t]*(?:[*+-]|\d+[.])[ \t]+)))/g;
+                text = text.replace(whole_list, function (wholeMatch, m1, m2, m3) {
+                    var runup = m1;
+                    var list = m2;
+
+                    var list_type = (m3.search(/[*+-]/g) > -1) ? "ul" : "ol";
+                    var result = _ProcessListItems(list, list_type);
+                    result = runup + "<" + list_type + ">\n" + result + "</" + list_type + ">\n";
+                    return result;
+                });
+            }
+
+            // attacklab: strip sentinel
+            text = text.replace(/~0/, "");
+
+            return text;
+        }
+
+        var _listItemMarkers = { ol: "\\d+[.]", ul: "[*+-]" };
+
+        function _ProcessListItems(list_str, list_type) {
+            //
+            //  Process the contents of a single ordered or unordered list, splitting it
+            //  into individual list items.
+            //
+            //  list_type is either "ul" or "ol".
+
+            // The $g_list_level global keeps track of when we're inside a list.
+            // Each time we enter a list, we increment it; when we leave a list,
+            // we decrement. If it's zero, we're not in a list anymore.
+            //
+            // We do this because when we're not inside a list, we want to treat
+            // something like this:
+            //
+            //    I recommend upgrading to version
+            //    8. Oops, now this line is treated
+            //    as a sub-list.
+            //
+            // As a single paragraph, despite the fact that the second line starts
+            // with a digit-period-space sequence.
+            //
+            // Whereas when we're inside a list (or sub-list), that line will be
+            // treated as the start of a sub-list. What a kludge, huh? This is
+            // an aspect of Markdown's syntax that's hard to parse perfectly
+            // without resorting to mind-reading. Perhaps the solution is to
+            // change the syntax rules such that sub-lists must start with a
+            // starting cardinal number; e.g. "1." or "a.".
+
+            g_list_level++;
+
+            // trim trailing blank lines:
+            list_str = list_str.replace(/\n{2,}$/, "\n");
+
+            // attacklab: add sentinel to emulate \z
+            list_str += "~0";
+
+            // In the original attacklab showdown, list_type was not given to this function, and anything
+            // that matched /[*+-]|\d+[.]/ would just create the next <li>, causing this mismatch:
+            //
+            //  Markdown          rendered by WMD        rendered by MarkdownSharp
+            //  ------------------------------------------------------------------
+            //  1. first          1. first               1. first
+            //  2. second         2. second              2. second
+            //  - third           3. third                   * third
+            //
+            // We changed this to behave identical to MarkdownSharp. This is the constructed RegEx,
+            // with {MARKER} being one of \d+[.] or [*+-], depending on list_type:
+        
+            /*
+            list_str = list_str.replace(/
+                (^[ \t]*)                       // leading whitespace = $1
+                ({MARKER}) [ \t]+               // list marker = $2
+                ([^\r]+?                        // list item text   = $3
+                    (\n+)
+                )
+                (?=
+                    (~0 | \2 ({MARKER}) [ \t]+)
+                )
+            /gm, function(){...});
+            */
+
+            var marker = _listItemMarkers[list_type];
+            var re = new RegExp("(^[ \\t]*)(" + marker + ")[ \\t]+([^\\r]+?(\\n+))(?=(~0|\\1(" + marker + ")[ \\t]+))", "gm");
+            var last_item_had_a_double_newline = false;
+            list_str = list_str.replace(re,
+                function (wholeMatch, m1, m2, m3) {
+                    var item = m3;
+                    var leading_space = m1;
+                    var ends_with_double_newline = /\n\n$/.test(item);
+                    var contains_double_newline = ends_with_double_newline || item.search(/\n{2,}/) > -1;
+
+                    if (contains_double_newline || last_item_had_a_double_newline) {
+                        item = _RunBlockGamut(_Outdent(item), /* doNotUnhash = */true);
+                    }
+                    else {
+                        // Recursion for sub-lists:
+                        item = _DoLists(_Outdent(item));
+                        item = item.replace(/\n$/, ""); // chomp(item)
+                        item = _RunSpanGamut(item);
+                    }
+                    last_item_had_a_double_newline = ends_with_double_newline;
+                    return "<li>" + item + "</li>\n";
+                }
+            );
+
+            // attacklab: strip sentinel
+            list_str = list_str.replace(/~0/g, "");
+
+            g_list_level--;
+            return list_str;
+        }
+
+        function _DoCodeBlocks(text) {
+            //
+            //  Process Markdown `<pre><code>` blocks.
+            //  
+
+            /*
+            text = text.replace(/
+                (?:\n\n|^)
+                (                               // $1 = the code block -- one or more lines, starting with a space/tab
+                    (?:
+                        (?:[ ]{4}|\t)           // Lines must start with a tab or a tab-width of spaces - attacklab: g_tab_width
+                        .*\n+
+                    )+
+                )
+                (\n*[ ]{0,3}[^ \t\n]|(?=~0))    // attacklab: g_tab_width
+            /g ,function(){...});
+            */
+
+            // attacklab: sentinel workarounds for lack of \A and \Z, safari\khtml bug
+            text += "~0";
+
+            text = text.replace(/(?:\n\n|^)((?:(?:[ ]{4}|\t).*\n+)+)(\n*[ ]{0,3}[^ \t\n]|(?=~0))/g,
+                function (wholeMatch, m1, m2) {
+                    var codeblock = m1;
+                    var nextChar = m2;
+
+                    codeblock = _EncodeCode(_Outdent(codeblock));
+                    codeblock = _Detab(codeblock);
+                    codeblock = codeblock.replace(/^\n+/g, ""); // trim leading newlines
+                    codeblock = codeblock.replace(/\n+$/g, ""); // trim trailing whitespace
+
+                    codeblock = "<pre><code>" + codeblock + "\n</code></pre>";
+
+                    return "\n\n" + codeblock + "\n\n" + nextChar;
+                }
+            );
+
+            // attacklab: strip sentinel
+            text = text.replace(/~0/, "");
+
+            return text;
+        }
+
+        function hashBlock(text) {
+            text = text.replace(/(^\n+|\n+$)/g, "");
+            return "\n\n~K" + (g_html_blocks.push(text) - 1) + "K\n\n";
+        }
+
+        function _DoCodeSpans(text) {
+            //
+            // * Backtick quotes are used for <code></code> spans.
+            // 
+            // * You can use multiple backticks as the delimiters if you want to
+            //   include literal backticks in the code span. So, this input:
+            //     
+            //      Just type ``foo `bar` baz`` at the prompt.
+            //     
+            //   Will translate to:
+            //     
+            //      <p>Just type <code>foo `bar` baz</code> at the prompt.</p>
+            //     
+            //   There's no arbitrary limit to the number of backticks you
+            //   can use as delimters. If you need three consecutive backticks
+            //   in your code, use four for delimiters, etc.
+            //
+            // * You can use spaces to get literal backticks at the edges:
+            //     
+            //      ... type `` `bar` `` ...
+            //     
+            //   Turns to:
+            //     
+            //      ... type <code>`bar`</code> ...
+            //
+
+            /*
+            text = text.replace(/
+                (^|[^\\])       // Character before opening ` can't be a backslash
+                (`+)            // $2 = Opening run of `
+                (               // $3 = The code block
+                    [^\r]*?
+                    [^`]        // attacklab: work around lack of lookbehind
+                )
+                \2              // Matching closer
+                (?!`)
+            /gm, function(){...});
+            */
+
+            text = text.replace(/(^|[^\\])(`+)([^\r]*?[^`])\2(?!`)/gm,
+                function (wholeMatch, m1, m2, m3, m4) {
+                    var c = m3;
+                    c = c.replace(/^([ \t]*)/g, ""); // leading whitespace
+                    c = c.replace(/[ \t]*$/g, ""); // trailing whitespace
+                    c = _EncodeCode(c);
+                    c = c.replace(/:\/\//g, "~P"); // to prevent auto-linking. Not necessary in code *blocks*, but in code spans. Will be converted back after the auto-linker runs.
+                    return m1 + "<code>" + c + "</code>";
+                }
+            );
+
+            return text;
+        }
+
+        function _EncodeCode(text) {
+            //
+            // Encode/escape certain characters inside Markdown code runs.
+            // The point is that in code, these characters are literals,
+            // and lose their special Markdown meanings.
+            //
+            // Encode all ampersands; HTML entities are not
+            // entities within a Markdown code span.
+            text = text.replace(/&/g, "&amp;");
+
+            // Do the angle bracket song and dance:
+            text = text.replace(/</g, "&lt;");
+            text = text.replace(/>/g, "&gt;");
+
+            // Now, escape characters that are magic in Markdown:
+            text = escapeCharacters(text, "\*_{}[]\\", false);
+
+            // jj the line above breaks this:
+            //---
+
+            //* Item
+
+            //   1. Subitem
+
+            //            special char: *
+            //---
+
+            return text;
+        }
+
+        function _DoItalicsAndBold(text) {
+
+            // <strong> must go first:
+            text = text.replace(/([\W_]|^)(\*\*|__)(?=\S)([^\r]*?\S[\*_]*)\2([\W_]|$)/g,
+            "$1<strong>$3</strong>$4");
+
+            text = text.replace(/([\W_]|^)(\*|_)(?=\S)([^\r\*_]*?\S)\2([\W_]|$)/g,
+            "$1<em>$3</em>$4");
+
+            return text;
+        }
+
+        function _DoBlockQuotes(text) {
+
+            /*
+            text = text.replace(/
+                (                           // Wrap whole match in $1
+                    (
+                        ^[ \t]*>[ \t]?      // '>' at the start of a line
+                        .+\n                // rest of the first line
+                        (.+\n)*             // subsequent consecutive lines
+                        \n*                 // blanks
+                    )+
+                )
+            /gm, function(){...});
+            */
+
+            text = text.replace(/((^[ \t]*>[ \t]?.+\n(.+\n)*\n*)+)/gm,
+                function (wholeMatch, m1) {
+                    var bq = m1;
+
+                    // attacklab: hack around Konqueror 3.5.4 bug:
+                    // "----------bug".replace(/^-/g,"") == "bug"
+
+                    bq = bq.replace(/^[ \t]*>[ \t]?/gm, "~0"); // trim one level of quoting
+
+                    // attacklab: clean up hack
+                    bq = bq.replace(/~0/g, "");
+
+                    bq = bq.replace(/^[ \t]+$/gm, "");     // trim whitespace-only lines
+                    bq = _RunBlockGamut(bq);             // recurse
+
+                    bq = bq.replace(/(^|\n)/g, "$1  ");
+                    // These leading spaces screw with <pre> content, so we need to fix that:
+                    bq = bq.replace(
+                            /(\s*<pre>[^\r]+?<\/pre>)/gm,
+                        function (wholeMatch, m1) {
+                            var pre = m1;
+                            // attacklab: hack around Konqueror 3.5.4 bug:
+                            pre = pre.replace(/^  /mg, "~0");
+                            pre = pre.replace(/~0/g, "");
+                            return pre;
+                        });
+
+                    return hashBlock("<blockquote>\n" + bq + "\n</blockquote>");
+                }
+            );
+            return text;
+        }
+
+        function _FormParagraphs(text, doNotUnhash) {
+            //
+            //  Params:
+            //    $text - string to process with html <p> tags
+            //
+
+            // Strip leading and trailing lines:
+            text = text.replace(/^\n+/g, "");
+            text = text.replace(/\n+$/g, "");
+
+            var grafs = text.split(/\n{2,}/g);
+            var grafsOut = [];
+            
+            var markerRe = /~K(\d+)K/;
+
+            //
+            // Wrap <p> tags.
+            //
+            var end = grafs.length;
+            for (var i = 0; i < end; i++) {
+                var str = grafs[i];
+
+                // if this is an HTML marker, copy it
+                if (markerRe.test(str)) {
+                    grafsOut.push(str);
+                }
+                else if (/\S/.test(str)) {
+                    str = _RunSpanGamut(str);
+                    str = str.replace(/^([ \t]*)/g, "<p>");
+                    str += "</p>"
+                    grafsOut.push(str);
+                }
+
+            }
+            //
+            // Unhashify HTML blocks
+            //
+            if (!doNotUnhash) {
+                end = grafsOut.length;
+                for (var i = 0; i < end; i++) {
+                    var foundAny = true;
+                    while (foundAny) { // we may need several runs, since the data may be nested
+                        foundAny = false;
+                        grafsOut[i] = grafsOut[i].replace(/~K(\d+)K/g, function (wholeMatch, id) {
+                            foundAny = true;
+                            return g_html_blocks[id];
+                        });
+                    }
+                }
+            }
+            return grafsOut.join("\n\n");
+        }
+
+        function _EncodeAmpsAndAngles(text) {
+            // Smart processing for ampersands and angle brackets that need to be encoded.
+
+            // Ampersand-encoding based entirely on Nat Irons's Amputator MT plugin:
+            //   http://bumppo.net/projects/amputator/
+            text = text.replace(/&(?!#?[xX]?(?:[0-9a-fA-F]+|\w+);)/g, "&amp;");
+
+            // Encode naked <'s
+            text = text.replace(/<(?![a-z\/?\$!])/gi, "&lt;");
+
+            return text;
+        }
+
+        function _EncodeBackslashEscapes(text) {
+            //
+            //   Parameter:  String.
+            //   Returns:    The string, with after processing the following backslash
+            //               escape sequences.
+            //
+
+            // attacklab: The polite way to do this is with the new
+            // escapeCharacters() function:
+            //
+            //     text = escapeCharacters(text,"\\",true);
+            //     text = escapeCharacters(text,"`*_{}[]()>#+-.!",true);
+            //
+            // ...but we're sidestepping its use of the (slow) RegExp constructor
+            // as an optimization for Firefox.  This function gets called a LOT.
+
+            text = text.replace(/\\(\\)/g, escapeCharacters_callback);
+            text = text.replace(/\\([`*_{}\[\]()>#+-.!])/g, escapeCharacters_callback);
+            return text;
+        }
+
+        function _DoAutoLinks(text) {
+
+            // note that at this point, all other URL in the text are already hyperlinked as <a href=""></a>
+            // *except* for the <http://www.foo.com> case
+
+            // automatically add < and > around unadorned raw hyperlinks
+            // must be preceded by space/BOF and followed by non-word/EOF character    
+            text = text.replace(/(^|\s)(https?|ftp)(:\/\/[-A-Z0-9+&@#\/%?=~_|\[\]\(\)!:,\.;]*[-A-Z0-9+&@#\/%=~_|\[\]])($|\W)/gi, "$1<$2$3>$4");
+
+            //  autolink anything like <http://example.com>
+            
+            var replacer = function (wholematch, m1) { return "<a href=\"" + m1 + "\">" + pluginHooks.plainLinkText(m1) + "</a>"; }
+            text = text.replace(/<((https?|ftp):[^'">\s]+)>/gi, replacer);
+
+            // Email addresses: <address@domain.foo>
+            /*
+            text = text.replace(/
+                <
+                (?:mailto:)?
+                (
+                    [-.\w]+
+                    \@
+                    [-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+
+                )
+                >
+            /gi, _DoAutoLinks_callback());
+            */
+
+            /* disabling email autolinking, since we don't do that on the server, either
+            text = text.replace(/<(?:mailto:)?([-.\w]+\@[-a-z0-9]+(\.[-a-z0-9]+)*\.[a-z]+)>/gi,
+                function(wholeMatch,m1) {
+                    return _EncodeEmailAddress( _UnescapeSpecialChars(m1) );
+                }
+            );
+            */
+            return text;
+        }
+
+        function _UnescapeSpecialChars(text) {
+            //
+            // Swap back in all the special characters we've hidden.
+            //
+            text = text.replace(/~E(\d+)E/g,
+                function (wholeMatch, m1) {
+                    var charCodeToReplace = parseInt(m1);
+                    return String.fromCharCode(charCodeToReplace);
+                }
+            );
+            return text;
+        }
+
+        function _Outdent(text) {
+            //
+            // Remove one level of line-leading tabs or spaces
+            //
+
+            // attacklab: hack around Konqueror 3.5.4 bug:
+            // "----------bug".replace(/^-/g,"") == "bug"
+
+            text = text.replace(/^(\t|[ ]{1,4})/gm, "~0"); // attacklab: g_tab_width
+
+            // attacklab: clean up hack
+            text = text.replace(/~0/g, "")
+
+            return text;
+        }
+
+        function _Detab(text) {
+            if (!/\t/.test(text))
+                return text;
+
+            var spaces = ["    ", "   ", "  ", " "],
+            skew = 0,
+            v;
+
+            return text.replace(/[\n\t]/g, function (match, offset) {
+                if (match === "\n") {
+                    skew = offset + 1;
+                    return match;
+                }
+                v = (offset - skew) % 4;
+                skew = offset + 1;
+                return spaces[v];
+            });
+        }
+
+        //
+        //  attacklab: Utility functions
+        //
+
+        var _problemUrlChars = /(?:["'*()[\]:]|~D)/g;
+
+        // hex-encodes some unusual "problem" chars in URLs to avoid URL detection problems 
+        function encodeProblemUrlChars(url) {
+            if (!url)
+                return "";
+
+            var len = url.length;
+
+            return url.replace(_problemUrlChars, function (match, offset) {
+                if (match == "~D") // escape for dollar
+                    return "%24";
+                if (match == ":") {
+                    if (offset == len - 1 || /[0-9\/]/.test(url.charAt(offset + 1)))
+                        return ":"
+                }
+                return "%" + match.charCodeAt(0).toString(16);
+            });
+        }
+
+
+        function escapeCharacters(text, charsToEscape, afterBackslash) {
+            // First we have to escape the escape characters so that
+            // we can build a character class out of them
+            var regexString = "([" + charsToEscape.replace(/([\[\]\\])/g, "\\$1") + "])";
+
+            if (afterBackslash) {
+                regexString = "\\\\" + regexString;
+            }
+
+            var regex = new RegExp(regexString, "g");
+            text = text.replace(regex, escapeCharacters_callback);
+
+            return text;
+        }
+
+
+        function escapeCharacters_callback(wholeMatch, m1) {
+            var charCodeToEscape = m1.charCodeAt(0);
+            return "~E" + charCodeToEscape + "E";
+        }
+
+    }; // end of the Markdown.Converter constructor
+
+})();

pagedown/static/pagedown/Markdown.Editor.js

+// needs Markdown.Converter.js at the moment
+
+(function () {
+
+    var util = {},
+        position = {},
+        ui = {},
+        doc = window.document,
+        re = window.RegExp,
+        nav = window.navigator,
+        SETTINGS = { lineLength: 72 },
+
+    // Used to work around some browser bugs where we can't use feature testing.
+        uaSniffed = {
+            isIE: /msie/.test(nav.userAgent.toLowerCase()),
+            isIE_5or6: /msie 6/.test(nav.userAgent.toLowerCase()) || /msie 5/.test(nav.userAgent.toLowerCase()),
+            isOpera: /opera/.test(nav.userAgent.toLowerCase())
+        };
+
+
+    // -------------------------------------------------------------------
+    //  YOUR CHANGES GO HERE
+    //
+    // I've tried to localize the things you are likely to change to 
+    // this area.
+    // -------------------------------------------------------------------
+
+    // The text that appears on the upper part of the dialog box when
+    // entering links.
+    var linkDialogText = "<p><b>Insert Hyperlink</b></p><p>http://example.com/ \"optional title\"</p>";
+    var imageDialogText = "<p><b>Insert Image</b></p><p>http://example.com/images/diagram.jpg \"optional title\"<br><br>Need <a href='http://www.google.com/search?q=free+image+hosting' target='_blank'>free image hosting?</a></p>";
+
+    // The default text that appears in the dialog input box when entering
+    // links.
+    var imageDefaultText = "http://";
+    var linkDefaultText = "http://";
+
+    var defaultHelpHoverTitle = "Markdown Editing Help";
+
+    // -------------------------------------------------------------------
+    //  END OF YOUR CHANGES
+    // -------------------------------------------------------------------
+
+    // help, if given, should have a property "handler", the click handler for the help button,
+    // and can have an optional property "title" for the button's tooltip (defaults to "Markdown Editing Help").
+    // If help isn't given, not help button is created.
+    //
+    // The constructed editor object has the methods:
+    // - getConverter() returns the markdown converter object that was passed to the constructor
+    // - run() actually starts the editor; should be called after all necessary plugins are registered. Calling this more than once is a no-op.
+    // - refreshPreview() forces the preview to be updated. This method is only available after run() was called.
+    Markdown.Editor = function (markdownConverter, idPostfix, help) {
+
+        idPostfix = idPostfix || "";
+
+        var hooks = this.hooks = new Markdown.HookCollection();
+        hooks.addNoop("onPreviewRefresh");       // called with no arguments after the preview has been refreshed
+        hooks.addNoop("postBlockquoteCreation"); // called with the user's selection *after* the blockquote was created; should return the actual to-be-inserted text
+        hooks.addFalse("insertImageDialog");     /* called with one parameter: a callback to be called with the URL of the image. If the application creates
+                                                  * its own image insertion dialog, this hook should return true, and the callback should be called with the chosen
+                                                  * image url (or null if the user cancelled). If this hook returns false, the default dialog will be used.
+                                                  */
+
+        this.getConverter = function () { return markdownConverter; }
+
+        var that = this,
+            panels;
+
+        this.run = function () {
+            if (panels)
+                return; // already initialized
+
+            panels = new PanelCollection(idPostfix);
+            var commandManager = new CommandManager(hooks);
+            var previewManager = new PreviewManager(markdownConverter, panels, function () { hooks.onPreviewRefresh(); });
+            var undoManager, uiManager;
+
+            if (!/\?noundo/.test(doc.location.href)) {
+                undoManager = new UndoManager(function () {
+                    previewManager.refresh();
+                    if (uiManager) // not available on the first call
+                        uiManager.setUndoRedoButtonStates();
+                }, panels);
+                this.textOperation = function (f) {
+                    undoManager.setCommandMode();
+                    f();
+                    that.refreshPreview();
+                }
+            }
+
+            uiManager = new UIManager(idPostfix, panels, undoManager, previewManager, commandManager, help);
+            uiManager.setUndoRedoButtonStates();
+
+            var forceRefresh = that.refreshPreview = function () { previewManager.refresh(true); };
+
+            forceRefresh();
+        };
+
+    }
+
+    // before: contains all the text in the input box BEFORE the selection.
+    // after: contains all the text in the input box AFTER the selection.
+    function Chunks() { }
+
+    // startRegex: a regular expression to find the start tag
+    // endRegex: a regular expresssion to find the end tag
+    Chunks.prototype.findTags = function (startRegex, endRegex) {
+
+        var chunkObj = this;
+        var regex;
+
+        if (startRegex) {
+
+            regex = util.extendRegExp(startRegex, "", "$");
+
+            this.before = this.before.replace(regex,
+                function (match) {
+                    chunkObj.startTag = chunkObj.startTag + match;
+                    return "";
+                });
+
+            regex = util.extendRegExp(startRegex, "^", "");
+
+            this.selection = this.selection.replace(regex,
+                function (match) {
+                    chunkObj.startTag = chunkObj.startTag + match;
+                    return "";
+                });
+        }
+
+        if (endRegex) {
+
+            regex = util.extendRegExp(endRegex, "", "$");
+
+            this.selection = this.selection.replace(regex,
+                function (match) {
+                    chunkObj.endTag = match + chunkObj.endTag;
+                    return "";
+                });
+
+            regex = util.extendRegExp(endRegex, "^", "");
+
+            this.after = this.after.replace(regex,
+                function (match) {
+                    chunkObj.endTag = match + chunkObj.endTag;
+                    return "";
+                });
+        }
+    };
+
+    // If remove is false, the whitespace is transferred
+    // to the before/after regions.
+    //
+    // If remove is true, the whitespace disappears.
+    Chunks.prototype.trimWhitespace = function (remove) {
+        var beforeReplacer, afterReplacer, that = this;
+        if (remove) {
+            beforeReplacer = afterReplacer = "";
+        } else {
+            beforeReplacer = function (s) { that.before += s; return ""; }
+            afterReplacer = function (s) { that.after = s + that.after; return ""; }
+        }
+        
+        this.selection = this.selection.replace(/^(\s*)/, beforeReplacer).replace(/(\s*)$/, afterReplacer);
+    };
+
+
+    Chunks.prototype.skipLines = function (nLinesBefore, nLinesAfter, findExtraNewlines) {
+
+        if (nLinesBefore === undefined) {
+            nLinesBefore = 1;
+        }
+
+        if (nLinesAfter === undefined) {
+            nLinesAfter = 1;
+        }
+
+        nLinesBefore++;
+        nLinesAfter++;
+
+        var regexText;
+        var replacementText;
+
+        // chrome bug ... documented at: http://meta.stackoverflow.com/questions/63307/blockquote-glitch-in-editor-in-chrome-6-and-7/65985#65985
+        if (navigator.userAgent.match(/Chrome/)) {
+            "X".match(/()./);
+        }
+
+        this.selection = this.selection.replace(/(^\n*)/, "");
+
+        this.startTag = this.startTag + re.$1;
+
+        this.selection = this.selection.replace(/(\n*$)/, "");
+        this.endTag = this.endTag + re.$1;
+        this.startTag = this.startTag.replace(/(^\n*)/, "");
+        this.before = this.before + re.$1;
+        this.endTag = this.endTag.replace(/(\n*$)/, "");
+        this.after = this.after + re.$1;
+
+        if (this.before) {
+
+            regexText = replacementText = "";
+
+            while (nLinesBefore--) {
+                regexText += "\\n?";
+                replacementText += "\n";
+            }
+
+            if (findExtraNewlines) {
+                regexText = "\\n*";
+            }
+            this.before = this.before.replace(new re(regexText + "$", ""), replacementText);
+        }
+
+        if (this.after) {
+
+            regexText = replacementText = "";
+
+            while (nLinesAfter--) {
+                regexText += "\\n?";
+                replacementText += "\n";
+            }
+            if (findExtraNewlines) {
+                regexText = "\\n*";
+            }
+
+            this.after = this.after.replace(new re(regexText, ""), replacementText);
+        }
+    };
+
+    // end of Chunks 
+
+    // A collection of the important regions on the page.
+    // Cached so we don't have to keep traversing the DOM.
+    // Also holds ieCachedRange and ieCachedScrollTop, where necessary; working around
+    // this issue:
+    // Internet explorer has problems with CSS sprite buttons that use HTML
+    // lists.  When you click on the background image "button", IE will 
+    // select the non-existent link text and discard the selection in the
+    // textarea.  The solution to this is to cache the textarea selection
+    // on the button's mousedown event and set a flag.  In the part of the
+    // code where we need to grab the selection, we check for the flag
+    // and, if it's set, use the cached area instead of querying the
+    // textarea.
+    //
+    // This ONLY affects Internet Explorer (tested on versions 6, 7
+    // and 8) and ONLY on button clicks.  Keyboard shortcuts work
+    // normally since the focus never leaves the textarea.
+    function PanelCollection(postfix) {
+        this.buttonBar = doc.getElementById("wmd-button-bar" + postfix);
+        this.preview = doc.getElementById("wmd-preview" + postfix);
+        this.input = doc.getElementById("wmd-input" + postfix);
+    };
+
+    // Returns true if the DOM element is visible, false if it's hidden.
+    // Checks if display is anything other than none.
+    util.isVisible = function (elem) {
+
+        if (window.getComputedStyle) {
+            // Most browsers
+            return window.getComputedStyle(elem, null).getPropertyValue("display") !== "none";
+        }
+        else if (elem.currentStyle) {
+            // IE
+            return elem.currentStyle["display"] !== "none";
+        }
+    };
+
+
+    // Adds a listener callback to a DOM element which is fired on a specified
+    // event.
+    util.addEvent = function (elem, event, listener) {
+        if (elem.attachEvent) {
+            // IE only.  The "on" is mandatory.
+            elem.attachEvent("on" + event, listener);
+        }
+        else {
+            // Other browsers.
+            elem.addEventListener(event, listener, false);
+        }
+    };
+
+
+    // Removes a listener callback from a DOM element which is fired on a specified
+    // event.
+    util.removeEvent = function (elem, event, listener) {
+        if (elem.detachEvent) {
+            // IE only.  The "on" is mandatory.
+            elem.detachEvent("on" + event, listener);
+        }
+        else {
+            // Other browsers.
+            elem.removeEventListener(event, listener, false);
+        }
+    };
+
+    // Converts \r\n and \r to \n.
+    util.fixEolChars = function (text) {
+        text = text.replace(/\r\n/g, "\n");
+        text = text.replace(/\r/g, "\n");
+        return text;
+    };
+
+    // Extends a regular expression.  Returns a new RegExp
+    // using pre + regex + post as the expression.
+    // Used in a few functions where we have a base
+    // expression and we want to pre- or append some
+    // conditions to it (e.g. adding "$" to the end).
+    // The flags are unchanged.
+    //
+    // regex is a RegExp, pre and post are strings.
+    util.extendRegExp = function (regex, pre, post) {
+
+        if (pre === null || pre === undefined) {
+            pre = "";
+        }
+        if (post === null || post === undefined) {
+            post = "";
+        }
+
+        var pattern = regex.toString();
+        var flags;
+
+        // Replace the flags with empty space and store them.
+        pattern = pattern.replace(/\/([gim]*)$/, function (wholeMatch, flagsPart) {
+            flags = flagsPart;
+            return "";
+        });
+
+        // Remove the slash delimiters on the regular expression.
+        pattern = pattern.replace(/(^\/|\/$)/g, "");
+        pattern = pre + pattern + post;
+
+        return new re(pattern, flags);
+    }
+
+    // UNFINISHED
+    // The assignment in the while loop makes jslint cranky.
+    // I'll change it to a better loop later.
+    position.getTop = function (elem, isInner) {
+        var result = elem.offsetTop;
+        if (!isInner) {
+            while (elem = elem.offsetParent) {
+                result += elem.offsetTop;
+            }
+        }
+        return result;
+    };
+
+    position.getHeight = function (elem) {
+        return elem.offsetHeight || elem.scrollHeight;
+    };
+
+    position.getWidth = function (elem) {
+        return elem.offsetWidth || elem.scrollWidth;
+    };
+
+    position.getPageSize = function () {
+
+        var scrollWidth, scrollHeight;
+        var innerWidth, innerHeight;
+
+        // It's not very clear which blocks work with which browsers.
+        if (self.innerHeight && self.scrollMaxY) {
+            scrollWidth = doc.body.scrollWidth;
+            scrollHeight = self.innerHeight + self.scrollMaxY;
+        }
+        else if (doc.body.scrollHeight > doc.body.offsetHeight) {
+            scrollWidth = doc.body.scrollWidth;
+            scrollHeight = doc.body.scrollHeight;
+        }
+        else {
+            scrollWidth = doc.body.offsetWidth;
+            scrollHeight = doc.body.offsetHeight;
+        }
+
+        if (self.innerHeight) {
+            // Non-IE browser
+            innerWidth = self.innerWidth;
+            innerHeight = self.innerHeight;
+        }
+        else if (doc.documentElement && doc.documentElement.clientHeight) {
+            // Some versions of IE (IE 6 w/ a DOCTYPE declaration)
+            innerWidth = doc.documentElement.clientWidth;
+            innerHeight = doc.documentElement.clientHeight;
+        }
+        else if (doc.body) {
+            // Other versions of IE
+            innerWidth = doc.body.clientWidth;
+            innerHeight = doc.body.clientHeight;
+        }
+
+        var maxWidth = Math.max(scrollWidth, innerWidth);
+        var maxHeight = Math.max(scrollHeight, innerHeight);
+        return [maxWidth, maxHeight, innerWidth, innerHeight];
+    };
+
+    // Handles pushing and popping TextareaStates for undo/redo commands.
+    // I should rename the stack variables to list.
+    function UndoManager(callback, panels) {
+
+        var undoObj = this;
+        var undoStack = []; // A stack of undo states
+        var stackPtr = 0; // The index of the current state
+        var mode = "none";
+        var lastState; // The last state
+        var timer; // The setTimeout handle for cancelling the timer
+        var inputStateObj;
+
+        // Set the mode for later logic steps.
+        var setMode = function (newMode, noSave) {
+            if (mode != newMode) {
+                mode = newMode;
+                if (!noSave) {
+                    saveState();
+                }
+            }
+
+            if (!uaSniffed.isIE || mode != "moving") {
+                timer = setTimeout(refreshState, 1);
+            }
+            else {
+                inputStateObj = null;
+            }
+        };
+
+        var refreshState = function (isInitialState) {
+            inputStateObj = new TextareaState(panels, isInitialState);
+            timer = undefined;
+        };
+
+        this.setCommandMode = function () {
+            mode = "command";
+            saveState();
+            timer = setTimeout(refreshState, 0);
+        };
+
+        this.canUndo = function () {
+            return stackPtr > 1;
+        };
+
+        this.canRedo = function () {
+            if (undoStack[stackPtr + 1]) {
+                return true;
+            }
+            return false;
+        };
+
+        // Removes the last state and restores it.
+        this.undo = function () {
+
+            if (undoObj.canUndo()) {
+                if (lastState) {
+                    // What about setting state -1 to null or checking for undefined?
+                    lastState.restore();
+                    lastState = null;
+                }
+                else {
+                    undoStack[stackPtr] = new TextareaState(panels);
+                    undoStack[--stackPtr].restore();
+
+                    if (callback) {
+                        callback();
+                    }
+                }
+            }
+
+            mode = "none";
+            panels.input.focus();
+            refreshState();
+        };
+
+        // Redo an action.
+        this.redo = function () {
+
+            if (undoObj.canRedo()) {
+
+                undoStack[++stackPtr].restore();
+
+                if (callback) {
+                    callback();
+                }
+            }
+
+            mode = "none";
+            panels.input.focus();
+            refreshState();
+        };
+
+        // Push the input area state to the stack.
+        var saveState = function () {
+            var currState = inputStateObj || new TextareaState(panels);
+
+            if (!currState) {
+                return false;
+            }
+            if (mode == "moving") {
+                if (!lastState) {
+                    lastState = currState;
+                }
+                return;
+            }
+            if (lastState) {
+                if (undoStack[stackPtr - 1].text != lastState.text) {
+                    undoStack[stackPtr++] = lastState;
+                }
+                lastState = null;
+            }
+            undoStack[stackPtr++] = currState;
+            undoStack[stackPtr + 1] = null;
+            if (callback) {
+                callback();
+            }
+        };
+
+        var handleCtrlYZ = function (event) {
+
+            var handled = false;
+
+            if (event.ctrlKey || event.metaKey) {
+
+                // IE and Opera do not support charCode.
+                var keyCode = event.charCode || event.keyCode;
+                var keyCodeChar = String.fromCharCode(keyCode);
+
+                switch (keyCodeChar) {
+
+                    case "y":
+                        undoObj.redo();
+                        handled = true;
+                        break;
+
+                    case "z":
+                        if (!event.shiftKey) {
+                            undoObj.undo();
+                        }
+                        else {
+                            undoObj.redo();
+                        }
+                        handled = true;
+                        break;
+                }
+            }
+
+            if (handled) {
+                if (event.preventDefault) {
+                    event.preventDefault();
+                }
+                if (window.event) {
+                    window.event.returnValue = false;
+                }
+                return;
+            }
+        };
+
+        // Set the mode depending on what is going on in the input area.
+        var handleModeChange = function (event) {
+
+            if (!event.ctrlKey && !event.metaKey) {
+
+                var keyCode = event.keyCode;
+
+                if ((keyCode >= 33 && keyCode <= 40) || (keyCode >= 63232 && keyCode <= 63235)) {
+                    // 33 - 40: page up/dn and arrow keys
+                    // 63232 - 63235: page up/dn and arrow keys on safari
+                    setMode("moving");
+                }