dont double escape certain entities/character references, fix encoding test

lib/marked.js

@@ -332,7 +332,7 @@ inline.lexer = function(str) {
     if (cap = inline.code.exec(str)) {
       str = str.substring(cap[0].length);
       out += '<code>'
-        + escape(cap[2] || cap[1])
+        + escape(cap[2] || cap[1], true)
         + '</code>';
       continue;
     }
@@ -413,7 +413,7 @@ var tok = function() {
     }
     case 'code': {
       return '<pre><code>'
-        + escape(token.text)
+        + escape(token.text, true)
         + '</code></pre>';
     }
     case 'blockquote_start': {
@@ -508,9 +508,11 @@ var parse = function(src) {
  * Helpers
  */
 
-var escape = function(html) {
+var escape = function(html, dbl) {
   return html
-    .replace(/&/g, '&amp;')
+    .replace(!dbl
+      ? /&(?!#?\w+;)/g
+      : /&/g, '&amp;')
     .replace(/</g, '&lt;')
     .replace(/>/g, '&gt;')
     .replace(/"/g, '&quot;')

test/fix.js

@@ -51,16 +51,11 @@ fs.readdirSync(dir).forEach(function(file) {
   fs.writeFileSync(file, text);
 });
 
-// markdown avoids double encoding half of the time
-// and does it the other half. this behavior will be
-// implemented eventually, but for now, this needs to 
-// be changed, because i want to see if the other tests
-// included in this file pass.
+// markdown is weird with encoding
 (function() {
   var file = dir + '/amps_and_angles_encoding.html';
   var html = fs.readFileSync(file, 'utf8')
     .replace('6 > 5.', '6 > 5.')
-    .replace('AT&T is another', 'AT&T is another');
 
   fs.writeFileSync(file, html);
 })();

test/tests/amps_and_angles_encoding.html

@@ -1,6 +1,6 @@
 <p>AT&amp;T has an ampersand in their name.</p>
 
-<p>AT&amp;amp;T is another way to write it.</p>
+<p>AT&amp;T is another way to write it.</p>
 
 <p>This &amp; that.</p>