UnboundMethod only refer defined_class

UnboundMethod records caller's class, like `D` or `E` on the
following case:

```ruby
class C
  def foo = :foo
end

class D < C
end

class E < C
end

d = D.instance_method(:foo)
e = E.instance_method(:foo)
```

But `d` and `e` only refers `C#foo` so that UnboundMethod doesn't
record `D` or `E`. This behavior changes the following methods:

* `UnboundMethod#inspect` (doesn't show caller's class)
* `UnboundMethod#==` (`d == e` for example)

fix https://bugs.ruby-lang.org/issues/18798

1 files changed, 6 insertions, 2 deletions

diff --git a/spec/ruby/core/module/instance_method_spec.rb b/spec/ruby/core/module/instance_method_spec.rb
index 30e27bb180..8d006e647e 100644
--- a/spec/ruby/core/module/instance_method_spec.rb
+++ b/spec/ruby/core/module/instance_method_spec.rb
@@ -45,10 +45,14 @@ describe "Module#instance_method" do
     @parent_um.inspect.should =~ /\bModuleSpecs::InstanceMeth\b/
     @child_um.inspect.should =~ /\bfoo\b/
     @child_um.inspect.should =~ /\bModuleSpecs::InstanceMeth\b/
-    @child_um.inspect.should =~ /\bModuleSpecs::InstanceMethChild\b/
+
     @mod_um.inspect.should =~ /\bbar\b/
     @mod_um.inspect.should =~ /\bModuleSpecs::InstanceMethMod\b/
-    @mod_um.inspect.should =~ /\bModuleSpecs::InstanceMethChild\b/
+
+    ruby_version_is ""..."3.2" do
+      @child_um.inspect.should =~ /\bModuleSpecs::InstanceMethChild\b/
+      @mod_um.inspect.should =~ /\bModuleSpecs::InstanceMethChild\b/
+    end
   end
 
   it "raises a TypeError if the given name is not a String/Symbol" do