backported req.is() charset fix

Author: tj

lib/request.js

@@ -292,16 +292,18 @@ req.flash = function(type, msg){
 req.is = function(type){
   var fn = this.app.is(type);
   if (fn) return fn(this);
-  var contentType = this.headers['content-type'];
-  if (!contentType) return;
+  var ct = this.headers['content-type'];
+  if (!ct) return false;
+  ct = ct.split(';')[0];
   if (!~type.indexOf('/')) type = mime.lookup(type);
   if (~type.indexOf('*')) {
-    type = type.split('/')
-    contentType = contentType.split('/');
-    if ('*' == type[0] && type[1] == contentType[1]) return true;
-    if ('*' == type[1] && type[0] == contentType[0]) return true;
+    type = type.split('/');
+    ct = ct.split('/');
+    if ('*' == type[0] && type[1] == ct[1]) return true;
+    if ('*' == type[1] && type[0] == ct[0]) return true;
+    return false;
   }
-  return !! ~contentType.indexOf(type);
+  return !! ~ct.indexOf(type);
 };
 
 // Callback for isXMLHttpRequest / xhr