From: matthew@...
Date: 2017-05-25T17:43:26+00:00
Subject: [ruby-core:81385] [Ruby trunk Bug#13574] Method redefinition warning

Issue #13574 has been updated by matthewd (Matthew Draper).


> What do you mean?
> That remove_method + new definition is not atomic?

Yes. Using remove_method + define_method, a concurrent thread may get a NoMethodError. In contrast, using alias_method + define_method, while the other thread could obviously call either the old or new definition (depending on exact timing), there will always be *a* method there.

----------------------------------------
Bug #13574: Method redefinition warning
https://bugs.ruby-lang.org/issues/13574#change-65094

* Author: tenderlovemaking (Aaron Patterson)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: ruby 2.5.0dev (2017-03-22 gc-compact 58059) [x86_64-darwin16]
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
Hi,

If I redefine a method like this, I get a warning:

~~~ruby
class Foo
  def bar
  end
end

class Foo
  def bar
  end
end
~~~

If I alias the method to a different name, I don't get a warning:

~~~ruby
class Foo
  def bar
  end
end

class Foo
  alias :foo :bar

  def bar
  end
end
~~~

I think this is expected.  However, if I alias the method to itself, I don't get a warning:

~~~ruby
class Foo
  def bar
  end
end

class Foo
  alias :bar :bar

  def bar
  end
end
~~~

I think this case should cause a warning.

---Files--------------------------------
warn-on-same-name-alias.diff (425 Bytes)


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