From 4d0129aefb3dd7ed71ffa172663e572679f4ef0e Mon Sep 17 00:00:00 2001
From: Pranshu Srivastava <rexagod@gmail.com>
Date: Sun, 26 Apr 2020 03:29:17 +0530
Subject: [PATCH] http2: do not modify explicity set date headers

Fixes: https://github.com/nodejs/node/issues/30894
Refs: https://github.com/nodejs/node/issues/29829

PR-URL: https://github.com/nodejs/node/pull/33160
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
---
 doc/api/http2.md                              | 10 +++++++++
 lib/internal/http2/core.js                    |  5 ++++-
 ...test-http2-removed-header-stays-removed.js | 22 +++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 test/parallel/test-http2-removed-header-stays-removed.js

diff --git a/doc/api/http2.md b/doc/api/http2.md
index c52b896da25217..d7397a3e72119c 100644
--- a/doc/api/http2.md
+++ b/doc/api/http2.md
@@ -1429,6 +1429,10 @@ and will throw an error.
 #### `http2stream.respond([headers[, options]])`
 <!-- YAML
 added: v8.4.0
+changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/33160
+    description: Allow explicity setting date headers.
 -->
 
 * `headers` {HTTP/2 Headers Object}
@@ -1473,6 +1477,9 @@ server.on('stream', (stream) => {
 <!-- YAML
 added: v8.4.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/33160
+    description: Allow explicity setting date headers.
   - version: v12.12.0
     pr-url: https://github.com/nodejs/node/pull/29876
     description: The `fd` option may now be a `FileHandle`.
@@ -1571,6 +1578,9 @@ server.on('stream', (stream) => {
 <!-- YAML
 added: v8.4.0
 changes:
+  - version: REPLACEME
+    pr-url: https://github.com/nodejs/node/pull/33160
+    description: Allow explicity setting date headers.
   - version: v10.0.0
     pr-url: https://github.com/nodejs/node/pull/18936
     description: Any readable file, not necessarily a
diff --git a/lib/internal/http2/core.js b/lib/internal/http2/core.js
index e9d786f2a6b312..4b0f3a805be5c6 100644
--- a/lib/internal/http2/core.js
+++ b/lib/internal/http2/core.js
@@ -2199,7 +2199,10 @@ function processHeaders(oldHeaders) {
   const statusCode =
     headers[HTTP2_HEADER_STATUS] =
       headers[HTTP2_HEADER_STATUS] | 0 || HTTP_STATUS_OK;
-  headers[HTTP2_HEADER_DATE] = utcDate();
+
+  if (headers[HTTP2_HEADER_DATE] === null ||
+      headers[HTTP2_HEADER_DATE] === undefined)
+    headers[HTTP2_HEADER_DATE] = utcDate();
 
   // This is intentionally stricter than the HTTP/1 implementation, which
   // allows values between 100 and 999 (inclusive) in order to allow for
diff --git a/test/parallel/test-http2-removed-header-stays-removed.js b/test/parallel/test-http2-removed-header-stays-removed.js
new file mode 100644
index 00000000000000..6ba7bba474d9b1
--- /dev/null
+++ b/test/parallel/test-http2-removed-header-stays-removed.js
@@ -0,0 +1,22 @@
+'use strict';
+const common = require('../common');
+if (!common.hasCrypto) { common.skip('missing crypto'); }
+const assert = require('assert');
+const http2 = require('http2');
+
+const server = http2.createServer(common.mustCall((request, response) => {
+  response.setHeader('date', 'snacks o clock');
+  response.end();
+}));
+
+server.listen(0, common.mustCall(() => {
+  const session = http2.connect(`http://localhost:${server.address().port}`);
+  const req = session.request();
+  req.on('response', (headers, flags) => {
+    assert.deepStrictEqual(headers.date, 'snacks o clock');
+  });
+  req.on('end', () => {
+    session.close();
+    server.close();
+  });
+}));