From df038ad90fbc0d47f5937a7f6b2b6a55f3c98d57 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E9=99=88=E5=88=9A?= <chengang07@meituan.com>
Date: Fri, 12 Jan 2018 23:21:44 +0800
Subject: [PATCH] fs: fix options.end of fs.ReadStream()

Fixes: https://github.com/nodejs/node/issues/18116
PR-URL: https://github.com/nodejs/node/pull/18121
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Weijia Wang <starkwang@126.com>
---
 lib/fs.js                            |  3 ++-
 test/parallel/test-fs-read-stream.js | 14 ++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/fs.js b/lib/fs.js
index e6ab7ba6d6986d..5efccceb544d20 100644
--- a/lib/fs.js
+++ b/lib/fs.js
@@ -1919,7 +1919,8 @@ function ReadStream(path, options) {
   this.flags = options.flags === undefined ? 'r' : options.flags;
   this.mode = options.mode === undefined ? 0o666 : options.mode;
 
-  this.start = options.start;
+  this.start = typeof this.fd !== 'number' && options.start === undefined ?
+    0 : options.start;
   this.end = options.end;
   this.autoClose = options.autoClose === undefined ? true : options.autoClose;
   this.pos = undefined;
diff --git a/test/parallel/test-fs-read-stream.js b/test/parallel/test-fs-read-stream.js
index bab809f72c19ce..95d5fbeaef9973 100644
--- a/test/parallel/test-fs-read-stream.js
+++ b/test/parallel/test-fs-read-stream.js
@@ -132,6 +132,20 @@ stream.on('end', function() {
   assert.strictEqual('x', stream.data);
 });
 
+{
+  // Verify that end works when start is not specified.
+  const stream = new fs.createReadStream(rangeFile, { end: 1 });
+  stream.data = '';
+
+  stream.on('data', function(chunk) {
+    stream.data += chunk;
+  });
+
+  stream.on('end', common.mustCall(function() {
+    assert.strictEqual('xy', stream.data);
+  }));
+}
+
 // pause and then resume immediately.
 const pauseRes = fs.createReadStream(rangeFile);
 pauseRes.pause();