[ruby-core:96808] [Ruby master Bug#16500] Argument is added to both splat and last &block argument

[eregontp@gmail.com]

Issue #16500 has been updated by Eregon (Benoit Daloze).


FWIW the 2.6 behavior is detailed in ruby/spec:
https://github.com/ruby/spec/blob/84d606aa8e85a8fef6521b3402dae612d04288c4/language/send_spec.rb#L424-L445
From commit
https://github.com/ruby/spec/commit/01992ab93dd893d9e8bf79db9f5ff7d250952097
which shows RubyGems used to rely on the 2.6 behavior.

What I want to say is existing code relies on 2.6 behavior.
It's probably good to always evaluate positional arguments before the block argument for consistency, but it's an incompatible change.

----------------------------------------
Bug #16500: Argument is added to both splat and last &block argument
https://bugs.ruby-lang.org/issues/16500#change-83803

* Author: anatolik (Anatol Pomozov)
* Status: Open
* Priority: Normal
* Assignee: ioquatix (Samuel Williams)
* Target version: 
* ruby -v: 2.7.0
* Backport: 2.5: UNKNOWN, 2.6: UNKNOWN, 2.7: UNKNOWN
----------------------------------------
Here is a followup for a ruby2.7 issue discussed here https://gitlab.com/groups/gitlab-org/-/epics/2380

I run gitlab with ruby2.7. gitlab/lib/api/api_guard.rb calls Rack's `use` method:


```ruby
use Rack::OAuth2::Server::Resource::Bearer, 'The API' do |request|
  # The authenticator only fetches the raw token string

  # Must yield access token to store it in the env
  request.access_token
end
```

The `use` method looks like:

```ruby
def use(middleware, *args, &block)
  if @map
    mapping, @map = @map, nil
      @use << proc { |app| generate_map app, mapping }
  end
  @use << proc { |app| middleware.new(app, *args, &block) }
end
```

For some reason, a `Proc` object was set to `&block` *and* added to `args`. It sounds wrong. A `Proc` should only be set to `&block`, and `args` should contain only one argument.



-- 
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