Avoid rewriting response.source to preserve existing API

lib/response.js

@@ -79,17 +79,14 @@ internals.Response.prototype._setSource = function (source, variety) {
     else if (source instanceof Stream) {
         this.variety = 'stream';
 
-        // Immediately convert classic readable streams to a streams2 readable
+        // Immediately wrap classic readable streams in a streams2 readable to preserve initial data
 
         var isReadable = (typeof source._read === 'function' && typeof source._readableState === 'object');
         if (!isReadable) {
             var isWritable = (typeof source._write === 'function' && typeof source._writableState === 'object');
             if (!isWritable && source.readable) {
-                var readable = new Stream.Readable().wrap(source);
-                readable.statusCode = source.statusCode;
-                readable.headers = source.headers;
-
-                source = readable;
+                this._payload = new Stream.Readable().wrap(source);
+                this._payload.source = source;
             }
         }
     }
@@ -461,6 +458,10 @@ internals.Response.prototype._marshal = function (next) {
 internals.Response.prototype._streamify = function (source, next) {
 
     if (source instanceof Stream) {
+        if (this._payload && this._payload.source === source) {      // Use cached payload from _setSource()
+            source = this._payload;
+        }
+
         if (typeof source._read !== 'function' || typeof source._readableState !== 'object') {
             return next(Boom.badImplementation('Reply stream must be readable'));
         }

lib/transmit.js

@@ -162,6 +162,8 @@ internals.fail = function (request, boom, callback) {
                 message: boom.message
             };
 
+            response._close();
+
             response._payload = new Response.Payload(JSON.stringify(minimal), {});
         }