From 4f54471e898858ed23eb4497e925879ded1a73e9 Mon Sep 17 00:00:00 2001
From: Diogo Franco <diogomfranco@gmail.com>
Date: Mon, 28 Nov 2016 13:34:44 +0900
Subject: [PATCH 1/3] Update parseHeaders to match node http behavior

Node ignores duplicate entries for certain HTTP headers.

It also always converts the `set-cookie` header into an array.
---
 lib/helpers/parseHeaders.js | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/lib/helpers/parseHeaders.js b/lib/helpers/parseHeaders.js
index da96796ac6..8af2cc7f1b 100644
--- a/lib/helpers/parseHeaders.js
+++ b/lib/helpers/parseHeaders.js
@@ -2,6 +2,15 @@
 
 var utils = require('./../utils');
 
+// Headers whose duplicates are ignored by node
+// c.f. https://nodejs.org/api/http.html#http_message_headers
+var ignoreDuplicateOf = [
+  'age', 'authorization', 'content-length', 'content-type', 'etag',
+  'expires', 'from', 'host', 'if-modified-since', 'if-unmodified-since',
+  'last-modified', 'location', 'max-forwards', 'proxy-authorization',
+  'referer', 'retry-after', 'user-agent'
+];
+
 /**
  * Parse headers into an object
  *
@@ -29,7 +38,14 @@ module.exports = function parseHeaders(headers) {
     val = utils.trim(line.substr(i + 1));
 
     if (key) {
-      parsed[key] = parsed[key] ? parsed[key] + ', ' + val : val;
+      if (parsed[key] && ignoreDuplicateOf.indexOf(key) >= 0) {
+        return;
+      }
+      if (key === 'set-cookie') {
+        parsed[key] = (parsed[key] ? parsed[key] : []).concat([val]);
+      } else {
+        parsed[key] = parsed[key] ? parsed[key] + ', ' + val : val;
+      }
     }
   });
 

From 48c41036c3087e05e0c0a5f0a58884ea79305715 Mon Sep 17 00:00:00 2001
From: Tyler Brown <tyler@tybro.io>
Date: Fri, 28 Apr 2017 23:54:56 -0400
Subject: [PATCH 2/3] add tests for new duplicate header handling

---
 test/specs/helpers/parseHeaders.spec.js | 28 ++++++++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/test/specs/helpers/parseHeaders.spec.js b/test/specs/helpers/parseHeaders.spec.js
index 93479644b6..738c8e6900 100644
--- a/test/specs/helpers/parseHeaders.spec.js
+++ b/test/specs/helpers/parseHeaders.spec.js
@@ -15,5 +15,31 @@ describe('helpers::parseHeaders', function () {
     expect(parsed['connection']).toEqual('keep-alive');
     expect(parsed['transfer-encoding']).toEqual('chunked');
   });
-});
 
+  it('should use array for set-cookie', function() {
+    var parsedZero = parseHeaders('');
+    var parsedSingle = parseHeaders(
+      'Set-Cookie: key=val;'
+    );
+    var parsedMulti = parseHeaders(
+      'Set-Cookie: key=val;\n' +
+      'Set-Cookie: key2=val2;\n'
+    );
+
+    expect(parsedZero['set-cookie']).toBeUndefined();
+    expect(parsedSingle['set-cookie']).toEqual(['key=val;']);
+    expect(parsedMulti['set-cookie']).toEqual(['key=val;', 'key2=val2;']);
+  });
+
+  it('should handle duplicates', function() {
+    var parsed = parseHeaders(
+      'Age: age-a\n' + // age is blacklisted to ignore duplicates
+      'Age: age-b\n' +
+      'Foo: foo-a\n' +
+      'Foo: foo-b\n'
+    );
+
+    expect(parsed['age']).toEqual('age-a');
+    expect(parsed['foo']).toEqual('foo-a, foo-b');
+  });
+});

From d29962a0515c29092025634d14977cc5b618585a Mon Sep 17 00:00:00 2001
From: Tyler Brown <tyler@tybro.io>
Date: Sat, 29 Apr 2017 00:10:48 -0400
Subject: [PATCH 3/3] clarify comment

---
 test/specs/helpers/parseHeaders.spec.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/specs/helpers/parseHeaders.spec.js b/test/specs/helpers/parseHeaders.spec.js
index 738c8e6900..db964d60b2 100644
--- a/test/specs/helpers/parseHeaders.spec.js
+++ b/test/specs/helpers/parseHeaders.spec.js
@@ -33,7 +33,7 @@ describe('helpers::parseHeaders', function () {
 
   it('should handle duplicates', function() {
     var parsed = parseHeaders(
-      'Age: age-a\n' + // age is blacklisted to ignore duplicates
+      'Age: age-a\n' + // age is in ignore duplicates blacklist
       'Age: age-b\n' +
       'Foo: foo-a\n' +
       'Foo: foo-b\n'