From: nobu@...
Date: 2018-01-07T07:43:14+00:00
Subject: [ruby-core:84684] [Ruby trunk Bug#13774] for methods defined from procs, the binding of the resulting bound_method.to_proc does not have access to the original proc's closure environment

Issue #13774 has been updated by nobu (Nobuyoshi Nakada).


Once a `Proc` is bound as a method, the context of that method is not same as the based `Proc`, `receiver` for instance.

```ruby
x = ->{}
o = Object.new
o.define_singleton_method(:x, x)
p x.binding.receiver #=> main
p o.method(:x).to_proc.binding.receiver #=> o
```


----------------------------------------
Bug #13774: for methods defined from procs, the binding of the resulting bound_method.to_proc does not have access to the original proc's closure environment
https://bugs.ruby-lang.org/issues/13774#change-69398

* Author: bughit (bug hit)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: ruby 2.5.0p0 (2017-12-25 revision 61468) [x86_64-linux]
* Backport: 2.2: UNKNOWN, 2.3: UNKNOWN, 2.4: UNKNOWN
----------------------------------------
```ruby
def foo
  o = Object.new
  local_var = 'local_var'
  method_lambda = ->{local_var}
  o.define_singleton_method(:lambda_method, &method_lambda)
  method_proc = o.method(:lambda_method).to_proc
  puts method_proc.()
  puts eval('local_var', method_lambda.binding)
  puts o.lambda_method
  puts eval('local_var', method_proc.binding) # undefined local variable or method `local_var'
end

foo
```

when executed as a method it has access to local_var as expected
but the binding of the bound method proc does not

in ruby 2.2.2 the above code crashes the vm



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