From 5792bd7149a30f7f43a739199d84603cc579f4e5 Mon Sep 17 00:00:00 2001
From: Thomas Marshall <thomas@thomasmarshall.com>
Date: Tue, 8 Oct 2024 17:30:51 +0100
Subject: [PATCH] Emit warning for other method redefinition types
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This commit ensures warnings about `object_id` and `__send__` method
redefinitions are emitted for other method types such as aliases, procs,
and attr readers—anything except C functions.
---
 test/ruby/test_object.rb | 31 +++++++++++++++++++++++--------
 vm_method.c              |  2 +-
 2 files changed, 24 insertions(+), 9 deletions(-)

diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
index 37c09596a2..3afad0ef43 100644
--- a/test/ruby/test_object.rb
+++ b/test/ruby/test_object.rb
@@ -480,15 +480,30 @@ class TestObject < Test::Unit::TestCase
   end
 
   def test_redefine_method_which_may_case_serious_problem
-    assert_in_out_err([], <<-INPUT, [], %r"warning: redefining 'object_id' may cause serious problems$")
-      $VERBOSE = false
-      def (Object.new).object_id; end
-    INPUT
+    %w(object_id __send__).each do |m|
+      assert_in_out_err([], <<-INPUT, [], %r"warning: redefining '#{m}' may cause serious problems$")
+        $VERBOSE = false
+        def (Object.new).#{m}; end
+      INPUT
 
-    assert_in_out_err([], <<-INPUT, [], %r"warning: redefining '__send__' may cause serious problems$")
-      $VERBOSE = false
-      def (Object.new).__send__; end
-    INPUT
+      assert_in_out_err([], <<-INPUT, [], %r"warning: redefining '#{m}' may cause serious problems$")
+        $VERBOSE = false
+        Class.new.define_method(:#{m}) {}
+      INPUT
+
+      assert_in_out_err([], <<-INPUT, [], %r"warning: redefining '#{m}' may cause serious problems$")
+        $VERBOSE = false
+        Class.new.attr_reader(:#{m})
+      INPUT
+
+      assert_in_out_err([], <<-INPUT, [], %r"warning: redefining '#{m}' may cause serious problems$")
+        $VERBOSE = false
+        Class.new do
+          def foo; end
+          alias #{m} foo
+        end
+      INPUT
+    end
 
     bug10421 = '[ruby-dev:48691] [Bug #10421]'
     assert_in_out_err([], <<-INPUT, ["1"], [], bug10421)
diff --git a/vm_method.c b/vm_method.c
index 4eb074bbd8..e436538f56 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -1062,7 +1062,7 @@ rb_method_entry_make(VALUE klass, ID mid, VALUE defined_class, rb_method_visibil
     }
     /* check mid */
     if (mid == object_id || mid == id__send__) {
-        if (type == VM_METHOD_TYPE_ISEQ && search_method(klass, mid, 0)) {
+        if (type != VM_METHOD_TYPE_CFUNC && search_method(klass, mid, 0)) {
             rb_warn("redefining '%s' may cause serious problems", rb_id2name(mid));
         }
     }