diff --git a/app/assets/javascripts/app/helpers/text_formatter.js b/app/assets/javascripts/app/helpers/text_formatter.js
index fe4069911..0759a6665 100644
--- a/app/assets/javascripts/app/helpers/text_formatter.js
+++ b/app/assets/javascripts/app/helpers/text_formatter.js
@@ -29,6 +29,8 @@
       text = text.replace(linkRegex, function() {
         var unicodeUrl = arguments[3];
         var addr = parse_url(unicodeUrl);
+        if( !addr.host ) addr.host = ""; // must not be 'undefined'
+
         var asciiUrl = // rebuild the url
           (!addr.scheme ? '' : addr.scheme +
           ( (addr.scheme.toLowerCase()=="mailto") ? ':' : '://')) +
diff --git a/vendor/assets/javascripts/jquery.mentionsInput.js b/vendor/assets/javascripts/jquery.mentionsInput.js
index a61746ac6..274f24404 100644
--- a/vendor/assets/javascripts/jquery.mentionsInput.js
+++ b/vendor/assets/javascripts/jquery.mentionsInput.js
@@ -200,8 +200,10 @@
     }
 
     function onInputBoxKeyPress(e) {
-      var typedValue = String.fromCharCode(e.which || e.keyCode);
-      inputBuffer.push(typedValue);
+      if(e.keyCode != KEY.BACKSPACE) {
+        var typedValue = String.fromCharCode(e.which || e.keyCode);
+        inputBuffer.push(typedValue);
+      }
     }
 
     function onInputBoxKeyDown(e) {