From 9dc21a946f725e5f8c12338c89f99521d37fe0c1 Mon Sep 17 00:00:00 2001
From: Zohaib Arif <zohaibarif619@gmail.com>
Date: Thu, 29 Jan 2026 14:37:06 +0500
Subject: [PATCH] readline: initialize input before history manager

---
 lib/internal/readline/interface.js             | 12 ++++++++----
 .../test-readline-history-init-order.js        | 18 ++++++++++++++++++
 2 files changed, 26 insertions(+), 4 deletions(-)
 create mode 100644 test/parallel/test-readline-history-init-order.js

diff --git a/lib/internal/readline/interface.js b/lib/internal/readline/interface.js
index 08f7aaa9e3e7e8..859ce3ebc398fd 100644
--- a/lib/internal/readline/interface.js
+++ b/lib/internal/readline/interface.js
@@ -215,7 +215,6 @@ function InterfaceConstructor(input, output, completer, terminal) {
     input.removeHistoryDuplicates = removeHistoryDuplicates;
   }
 
-  this.setupHistoryManager(input);
 
   if (completer !== undefined && typeof completer !== 'function') {
     throw new ERR_INVALID_ARG_VALUE('completer', completer);
@@ -234,6 +233,7 @@ function InterfaceConstructor(input, output, completer, terminal) {
   this[kSubstringSearch] = null;
   this.output = output;
   this.input = input;
+  this.setupHistoryManager(input);
   this[kUndoStack] = [];
   this[kRedoStack] = [];
   this[kPreviousCursorCols] = -1;
@@ -384,9 +384,13 @@ class Interface extends InterfaceConstructor {
   setupHistoryManager(options) {
     this.historyManager = new ReplHistory(this, options);
 
-    if (options.onHistoryFileLoaded) {
-      this.historyManager.initialize(options.onHistoryFileLoaded);
-    }
+    // Only initialize REPL history when createInterface()
+  // was called with an options object (options.input).
+  // This prevents accidental REPL history init when
+  // createInterface(input) is used.
+  if (options?.input && typeof options.onHistoryFileLoaded === 'function') {
+    this.historyManager.initialize(options.onHistoryFileLoaded);
+  }
 
     ObjectDefineProperty(this, 'history', {
       __proto__: null, configurable: true, enumerable: true,
diff --git a/test/parallel/test-readline-history-init-order.js b/test/parallel/test-readline-history-init-order.js
new file mode 100644
index 00000000000000..41bcd70b49b26c
--- /dev/null
+++ b/test/parallel/test-readline-history-init-order.js
@@ -0,0 +1,18 @@
+'use strict';
+
+const assert = require('assert');
+const readline = require('readline');
+const { PassThrough } = require('stream');
+
+assert.doesNotThrow(() => {
+  const input = new PassThrough();
+
+  // This simulates the condition that previously caused
+  // accidental REPL history initialization.
+  input.onHistoryFileLoaded = () => {};
+
+  readline.createInterface({
+    input,
+    output: new PassThrough()
+  });
+});