Added target="_blank" to hyperlinks in Markdown.Converter.js so that clicking on a link opens it in a new window. Fixes Issue #1701 and adds surrounding quotes.

IPython/frontend/html/notebook/static/pagedown/Markdown.Converter.js

@@ -1,1318 +1,1319
 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 = _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;
             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 = title.replace(/"/g, "&quot;");
                 title = escapeCharacters(title, "*_");
                 result += " title=\"" + title + "\"";
             }
 
-            result += ">" + link_text + "</a>";
+            result += " target=\"_blank\">" + 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 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 = alt_text.replace(/"/g, "&quot;");
             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 = title.replace(/"/g, "&quot;");
             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);
                     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 = [];
 
             //
             // 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 (str.search(/~K(\d+)K/g) >= 0) {
                     grafsOut.push(str);
                 }
                 else if (str.search(/\S/) >= 0) {
                     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++) {
                     // if this is a marker for an html block...
                     while (grafsOut[i].search(/~K(\d+)K/) >= 0) {
                         var blockText = g_html_blocks[RegExp.$1];
                         blockText = blockText.replace(/\$/g, "$$$$"); // Escape any dollar signs
                         grafsOut[i] = grafsOut[i].replace(/~K\d+K/, blockText);
                     }
                 }
             }
             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>
+            // note that at this point, all other URL in the text are already 
+            // hyperlinked as <a href="" target="_blank"></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>"; }
+            var replacer = function (wholematch, m1) { return "<a href=\"" + m1 + "\" target=\"_blank\"">" + pluginHooks.plainLinkText(m1) + "</a>"; }
             text = text.replace(/<((https?|ftp):[^'">\s]+)>/gi, replacer);
 
             // Email addresses: <[e-mail]>
             /*
             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
 
 })();