[fix] http-proxy should not modify the protocol in redirect request for external sites. Fixes #359.

Author: indexzero

Diff for: lib/node-http-proxy/http-proxy.js

@@ -27,6 +27,7 @@
 var events = require('events'),
     http = require('http'),
     util = require('util'),
+    url = require('url'),
     httpProxy = require('../node-http-proxy');
 
 //
@@ -122,7 +123,8 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
   var self = this,
       errState = false,
       outgoing = new(this.target.base),
-      reverseProxy;
+      reverseProxy,
+      location;
 
   //
   // Add common proxy headers to the request so that they can
@@ -257,11 +259,14 @@ HttpProxy.prototype.proxyRequest = function (req, res, buffer) {
 
     if ((response.statusCode === 301) || (response.statusCode === 302)
       && typeof response.headers.location !== 'undefined') {
-      if (self.source.https && !self.target.https) {
-        response.headers.location = response.headers.location.replace(/^http\:/, 'https:');
-      }
-      if (self.target.https && !self.source.https) {
-        response.headers.location = response.headers.location.replace(/^https\:/, 'http:');
+      location = url.parse(response.headers.location);
+      if (location.host === req.headers.host) {
+        if (self.source.https && !self.target.https) {
+          response.headers.location = response.headers.location.replace(/^http\:/, 'https:');
+        }
+        if (self.target.https && !self.source.https) {
+          response.headers.location = response.headers.location.replace(/^https\:/, 'http:');
+        }
       }
     }