From 2f7319e3875138ff0b4509ffc804e9824ae3720c Mon Sep 17 00:00:00 2001
From: Antoine du Hamel <duhamelantoine1995@gmail.com>
Date: Tue, 24 Jan 2023 13:10:11 +0100
Subject: [PATCH] readline: fix detection of carriage return

Fixes: https://github.com/nodejs/node/issues/45992
PR-URL: https://github.com/nodejs/node/pull/46306
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Yagiz Nizipli <yagiz@nizipli.com>
---
 lib/internal/readline/interface.js            |  1 +
 .../test-readline-big-file-carriage-return.js | 42 -------------------
 ...readline-carriage-return-between-chunks.js | 23 ++++++++++
 3 files changed, 24 insertions(+), 42 deletions(-)
 delete mode 100644 test/known_issues/test-readline-big-file-carriage-return.js
 create mode 100644 test/parallel/test-readline-carriage-return-between-chunks.js

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 937f426615c1b9..2e9d43626be402 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -597,6 +597,7 @@ class Interface extends InterfaceConstructor {
       if (this[kLine_buffer]) {
         string = this[kLine_buffer] + string;
         this[kLine_buffer] = null;
+        lineEnding.lastIndex = 0; // Start the search from the beginning of the string.
         newPartContainsEnding = RegExpPrototypeExec(lineEnding, string);
       }
       this[kSawReturnAt] = StringPrototypeEndsWith(string, '\r') ?
diff --git a/test/known_issues/test-readline-big-file-carriage-return.js b/test/known_issues/test-readline-big-file-carriage-return.js
deleted file mode 100644
index 7dfc918927eb26..00000000000000
--- a/test/known_issues/test-readline-big-file-carriage-return.js
+++ /dev/null
@@ -1,42 +0,0 @@
-'use strict';
-
-// Context: https://github.com/nodejs/node/issues/45992
-
-require('../common');
-
-const assert = require('assert');
-const fs = require('fs');
-const readline = require('readline');
-
-const tmpdir = require('../common/tmpdir');
-
-tmpdir.refresh();
-fs.mkdtempSync(`${tmpdir.path}/`);
-const path = `${tmpdir.path}/foo`;
-const writeStream = fs.createWriteStream(path);
-
-function write(iteration, callback) {
-  for (; iteration < 16384; iteration += 1) {
-    if (!writeStream.write('foo\r\n')) {
-      writeStream.once('drain', () => write(iteration + 1, callback));
-      return;
-    }
-  }
-
-  writeStream.end();
-  callback();
-}
-
-write(0, () => {
-  const input = fs.createReadStream(path);
-  const rl = readline.createInterface({ input, crlfDelay: Infinity });
-  let carriageReturns = 0;
-
-  rl.on('line', (x) => {
-    if (x.includes('\r')) carriageReturns += 1;
-  });
-
-  rl.on('close', () => {
-    assert.strictEqual(carriageReturns, 0);
-  });
-});
diff --git a/test/parallel/test-readline-carriage-return-between-chunks.js b/test/parallel/test-readline-carriage-return-between-chunks.js
new file mode 100644
index 00000000000000..aff012de5a9e5c
--- /dev/null
+++ b/test/parallel/test-readline-carriage-return-between-chunks.js
@@ -0,0 +1,23 @@
+'use strict';
+
+const common = require('../common');
+
+const assert = require('node:assert');
+const readline = require('node:readline');
+const { Readable } = require('node:stream');
+
+
+const input = Readable.from((function*() {
+  yield 'a\nb';
+  yield '\r\n';
+})());
+const rl = readline.createInterface({ input, crlfDelay: Infinity });
+let carriageReturns = 0;
+
+rl.on('line', (line) => {
+  if (line.includes('\r')) carriageReturns++;
+});
+
+rl.on('close', common.mustCall(() => {
+  assert.strictEqual(carriageReturns, 0);
+}));