From 5b0a6c6080b64b05334553455c35161fed35eb10 Mon Sep 17 00:00:00 2001
From: Alex Cabello <alexander.cabello@gmail.com>
Date: Tue, 13 Dec 2016 00:18:53 -1000
Subject: [PATCH] Preserve header case for incoming requests.

---
 lib/http-proxy/common.js | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/lib/http-proxy/common.js b/lib/http-proxy/common.js
index aa9700234..9c0a63b25 100644
--- a/lib/http-proxy/common.js
+++ b/lib/http-proxy/common.js
@@ -25,7 +25,7 @@ common.isSSL = isSSL;
  * @param {Object} Options Config object passed to the proxy
  * @param {ClientRequest} Req Request Object
  * @param {String} Forward String to select forward or target
- * 
+ * 
  * @return {Object} Outgoing Object with all required properties set
  *
  * @api private
@@ -41,7 +41,24 @@ common.setupOutgoing = function(outgoing, options, req, forward) {
   );
 
   outgoing.method = req.method;
-  outgoing.headers = extend({}, req.headers);
+
+  var connectionHeaderName = 'connection';
+  var hostHeaderName = 'host';
+  if (options.preserveHeaderKeyCase && req.rawHeaders != undefined) {
+    var rawHeaders = {};
+    for (var i = 0; i < req.rawHeaders.length - 1; i += 2) {
+      var key = req.rawHeaders[i];
+      rawHeaders[key] = req.rawHeaders[i + 1];
+
+      if(key.toLowerCase() === connectionHeaderName)
+        connectionHeaderName = key;
+      else if(key.toLowerCase() === hostHeaderName)
+        hostHeaderName = key;
+    }
+    outgoing.headers = extend({}, rawHeaders);
+  }  else {
+    outgoing.headers = extend({}, req.headers);
+  }
 
   if (options.headers){
     extend(outgoing.headers, options.headers);
@@ -69,9 +86,9 @@ common.setupOutgoing = function(outgoing, options, req, forward) {
   //
   if (!outgoing.agent) {
     outgoing.headers = outgoing.headers || {};
-    if (typeof outgoing.headers.connection !== 'string'
-        || !upgradeHeader.test(outgoing.headers.connection)
-       ) { outgoing.headers.connection = 'close'; }
+    if (typeof outgoing.headers[connectionHeaderName] !== 'string'
+        || !upgradeHeader.test(outgoing.headers[connectionHeaderName])
+       ) { outgoing.headers[connectionHeaderName] = 'close'; }
   }
 
 
@@ -98,7 +115,7 @@ common.setupOutgoing = function(outgoing, options, req, forward) {
   outgoing.path = common.urlJoin(targetPath, outgoingPath);
 
   if (options.changeOrigin) {
-    outgoing.headers.host =
+    outgoing.headers[hostHeaderName] =
       required(outgoing.port, options[forward || 'target'].protocol) && !hasPort(outgoing.host)
         ? outgoing.host + ':' + outgoing.port
         : outgoing.host;
@@ -117,7 +134,7 @@ common.setupOutgoing = function(outgoing, options, req, forward) {
  *    // => Socket
  *
  * @param {Socket} Socket instance to setup
- * 
+ * 
  * @return {Socket} Return the configured socket.
  *
  * @api private