fix reference link impostors

src/subParsers/stripLinkDefinitions.js

@@ -6,14 +6,19 @@
 showdown.subParser('stripLinkDefinitions', function (text, options, globals) {
   'use strict';
 
-  var regex       = /^ {0,3}\[(.+)]:[ \t]*\n?[ \t]*<?([^>\s]+)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*\n?[ \t]*(?:(\n*)["|'(](.+?)["|')][ \t]*)?(?:\n+|(?=¨0))/gm,
+  var regex       = /^ {0,3}\[([^\]]+)]:[ \t]*\n?[ \t]*<?([^>\s]+)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*\n?[ \t]*(?:(\n*)["|'(](.+?)["|')][ \t]*)?(?:\n+|(?=¨0))/gm,
-      base64Regex = /^ {0,3}\[(.+)]:[ \t]*\n?[ \t]*<?(data:.+?\/.+?;base64,[A-Za-z0-9+/=\n]+?)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*\n?[ \t]*(?:(\n*)["|'(](.+?)["|')][ \t]*)?(?:\n\n|(?=¨0)|(?=\n\[))/gm;
+      base64Regex = /^ {0,3}\[([^\]]+)]:[ \t]*\n?[ \t]*<?(data:.+?\/.+?;base64,[A-Za-z0-9+/=\n]+?)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*\n?[ \t]*(?:(\n*)["|'(](.+?)["|')][ \t]*)?(?:\n\n|(?=¨0)|(?=\n\[))/gm;
 
   // attacklab: sentinel workarounds for lack of \A and \Z, safari\khtml bug
   text += '¨0';
 
   var replaceFunc = function (wholeMatch, linkId, url, width, height, blankLines, title) {
+
+    // if there aren't two instances of linkId it must not be a reference link so back out
     linkId = linkId.toLowerCase();
+    if (text.toLowerCase().split(linkId).length - 1 < 2) {
+      return wholeMatch;
+    }
     if (url.match(/^data:.+?\/.+?;base64,/)) {
       // remove newlines
       globals.gUrls[linkId] = url.replace(/\s/g, '');

test/issues/reference-link-impostors.html

@@ -0,0 +1,3 @@
+<p>[We] are going to show [you]: sunshine!</p>
+<p>[x]: take out the garbage<br />
+[ ]: bring up the coal</p>

test/issues/reference-link-impostors.md

@@ -0,0 +1,4 @@
+[We] are going to show [you]: sunshine!
+
+[x]: take out the garbage  
+[ ]: bring up the coal