Call the callback with an error if the request is aborted.

The callback should always get called no matter what, to not do so breaks assumptions that hold for most other node libraries.

lib/incoming_form.js

@@ -115,6 +115,9 @@ IncomingForm.prototype.parse = function(req, cb) {
       })
       .on('end', function() {
         cb(null, fields, files);
+      })
+      .on('aborted', function () {
+        cb(new Error('Request aborted'), fields, files); 
       });
   }