Better handle extraneous </a> tags in the input HTML.

Author: gregjacobs

README.md

@@ -148,6 +148,11 @@ autolinker.link( "Go to www.google.com" );
 
 ## Changelog:
 
+### 0.9.1
+
+- Added a patch to attempt to better handle extraneous </a> tags in the input string if any exist. This is for when the
+  input may have some invalid markup (for instance, on sites which allow user comments, blog posts, etc.).
+
 ### 0.9.0
 
 - Added better support for the processing of existing HTML in the input string. Now handles namespaced tags, and attribute names 

dist/Autolinker.js

@@ -1,6 +1,6 @@
 /*!
  * autolinker
- * 0.9.0
+ * 0.9.1
  *
  * Copyright(c) 2014 Gregory Jacobs <[email protected]>
  * MIT Licensed. http://www.opensource.org/licenses/mit-license.php
@@ -299,7 +299,7 @@
 						resultHtml.push( this.processTextNode( inBetweenTagsText ) );
 
 					} else {   // it's the end </a> tag
-						anchorTagStackCount--;	
+						anchorTagStackCount = Math.max( anchorTagStackCount - 1, 0 );  // attempt to handle extraneous </a> tags by making sure the stack count never goes below 0
 						if( anchorTagStackCount === 0 ) {
 							resultHtml.push( inBetweenTagsText );  // We hit the matching </a> tag, simply add all of the text from the start <a> tag to the end </a> tag without linking it
 						}

dist/Autolinker.min.js

@@ -1,6 +1,6 @@
 {
   "name": "autolinker",
-  "version": "0.9.0",
+  "version": "0.9.1",
   "description": "Simple utility to automatically link the URLs, email addresses, and Twitter handles in a given block of text/HTML",
   "main": "dist/Autolinker.js",
   "directories": {

package.json

@@ -290,7 +290,7 @@
 						resultHtml.push( this.processTextNode( inBetweenTagsText ) );
 
 					} else {   // it's the end </a> tag
-						anchorTagStackCount--;	
+						anchorTagStackCount = Math.max( anchorTagStackCount - 1, 0 );  // attempt to handle extraneous </a> tags by making sure the stack count never goes below 0
 						if( anchorTagStackCount === 0 ) {
 							resultHtml.push( inBetweenTagsText );  // We hit the matching </a> tag, simply add all of the text from the start <a> tag to the end </a> tag without linking it
 						}

src/Autolinker.js

@@ -274,6 +274,40 @@ describe( "Autolinker", function() {
 					'</div>'
 				].join( "" ) );
 			} );
+			
+			
+			it( "should attempt to handle some invalid HTML markup relating to <a> tags, esp if there are extraneous closing </a> tags", function() {
+				var html = '</a><a href="http://google.com">google.com</a>';
+				
+				var result = Autolinker.link( html, { newWindow: false } );
+				expect( result ).toBe( html );
+			} );
+			
+			
+			it( "should attempt to handle some more complex invalid HTML markup relating to <a> tags, esp if there are extraneous closing </a> tags", function() {
+				var html = [
+					'</a>',  // invalid
+					'<a href="http://google.com">google.com</a>',
+					'<div>google.com</div>',
+					'</a>',  // invalid
+					'<a href="http://yahoo.com">yahoo.com</a>',
+					'</a>',  // invalid
+					'</a>',  // invalid
+					'twitter.com'
+				].join( "" );
+				
+				var result = Autolinker.link( html, { newWindow: false } );
+				expect( result ).toBe( [
+					'</a>',                                                   // invalid - left alone
+					'<a href="http://google.com">google.com</a>',             // valid tag - left alone
+					'<div><a href="http://google.com">google.com</a></div>',  // autolinked text in <div>
+					'</a>',                                                   // invalid - left alone
+					'<a href="http://yahoo.com">yahoo.com</a>',               // valid tag - left alone
+					'</a>',                                                   // invalid - left alone
+					'</a>',                                                   // invalid - left alone
+					'<a href="http://twitter.com">twitter.com</a>'            // autolinked text
+				].join( "" ) );
+			} );
 
 		} );