From 1b06142f50099827c208968258f08688a816467c Mon Sep 17 00:00:00 2001
From: KBS <youdie006@naver.com>
Date: Mon, 28 Sep 2026 21:00:05 +0900
Subject: [PATCH] Load a .rb file only once in irb_require

irb_load returns the value of eval_input, which is nil, so the
'if irb_load(file_name)' branch never recorded the file and fell through
to Kernel#require, which loaded it a second time. Call irb_load without
the check, as the no-extension branch does.
---
 lib/irb/command/load.rb  |  7 +++----
 test/irb/test_command.rb | 15 +++++++++++++++
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/lib/irb/command/load.rb b/lib/irb/command/load.rb
index 1efe23243..4792785c5 100644
--- a/lib/irb/command/load.rb
+++ b/lib/irb/command/load.rb
@@ -51,10 +51,9 @@ def execute_internal(file_name = nil)
         case file_name
         when /\.rb$/
           begin
-            if irb_load(file_name)
-              $".push file_name
-              return true
-            end
+            irb_load(file_name)
+            $".push file_name
+            return true
           rescue LoadError
           end
         when /\.(so|o|sl)$/
diff --git a/test/irb/test_command.rb b/test/irb/test_command.rb
index 1a99bc7eb..8fb20a22b 100644
--- a/test/irb/test_command.rb
+++ b/test/irb/test_command.rb
@@ -495,6 +495,21 @@ def test_irb_require_skips_file_already_loaded_by_require
       assert_match(/prefix_loaded/, out)
     end
 
+    def test_irb_require_loads_file_with_rb_extension_once
+      File.write("#{@tmpdir}/irb_require_rb_ext.rb", "$irb_require_rb_ext_count += 1\n")
+
+      out, err = execute_lines(
+        "$LOAD_PATH.unshift '#{@tmpdir}'\n",
+        "$irb_require_rb_ext_count = 0\n",
+        "irb_require 'irb_require_rb_ext.rb'\n",
+        "irb_require 'irb_require_rb_ext'\n",
+        "$irb_require_rb_ext_count\n",
+      )
+
+      assert_empty(err)
+      assert_match(/=> 1\n\z/, out)
+    end
+
     def test_irb_require_falls_back_to_kernel_require_when_not_in_load_path
       code = <<~RUBY
         p 'fallback_loaded'