http: don't unset hot path for responses with body

Revert a regression introduced when avoiding extra bytes for HEAD
requests, we shouldn't drop out of the hot path when responses will have
a body.

lib/http.js

@@ -954,6 +954,7 @@ OutgoingMessage.prototype.end = function(data, encoding) {
     //   res.writeHead();
     //   res.end(blah);
     // HACKY.
+    debug('we have hot path');
 
     if (typeof data === 'string') {
       if (this.chunkedEncoding) {
@@ -1586,11 +1587,21 @@ function socketOnData(d, start, end) {
 
   var ret = parser.execute(d, start, end - start);
   if (ret instanceof Error) {
-    debug('parse error');
-    freeParser(parser, req);
-    socket.destroy();
-    req.emit('error', ret);
-    req._hadError = true;
+    var response = parser.incoming;
+    if (response &&
+        response.headers['transfer-encoding'] === 'chunked' &&
+        response.complete &&
+        EventEmitter.listenerCount(response, 'chunkedRemainingBytes') > 0) {
+      var buff = d.slice(start + ret.bytesParsed, end);
+      debug('chunked encoding stream had extra bytes ' + ret.bytesParsed + ' ' + buff.length);
+      response.emit('chunkedRemainingBytes', buff);
+    } else {
+      debug('parse error');
+      freeParser(parser, req);
+      socket.destroy();
+      req.emit('error', ret);
+      req._hadError = true;
+    }
   } else if (parser.incoming && parser.incoming.upgrade) {
     // Upgrade or CONNECT
     var bytesParsed = ret;