Guard against emitting 'end' twice on http responses

lib/http.js

@@ -125,7 +125,10 @@ function parserOnMessageComplete() {
   if (!parser.incoming.upgrade) {
     // For upgraded connections, also emit this after parser.execute
     parser.incoming.readable = false;
-    parser.incoming.emit('end');
+    if (!parser.incoming._ended) {
+      parser.incoming._ended = true;
+      parser.incoming.emit('end');
+    }
   }
 
   if (parser.socket.readable) {
@@ -1158,7 +1161,10 @@ function socketCloseListener() {
   if (req.res && req.res.readable) {
     // Socket closed before we emitted "end" below.
     req.res.emit('aborted');
-    req.res.emit('end');
+    if (!req.res._ended) {
+      req.res._ended = true;
+      req.res.emit('end');
+    }
     req.res.emit('close');
   } else if (!req.res && !req._hadError) {
     // This socket error fired before we started to