From: "mame (Yusuke Endoh)" <mame@...>
Date: 2012-04-21T01:46:42+09:00
Subject: [ruby-core:44496] [ruby-trunk - Bug #5761][Closed] Array#flatten(N) calls to_ary on the (N+1)-level objects


Issue #5761 has been updated by mame (Yusuke Endoh).

Status changed from Assigned to Closed

This is already fixed in ruby-1.9.3-p194.

-- 
Yusuke Endoh <mame@tsg.ne.jp>
----------------------------------------
Bug #5761: Array#flatten(N) calls to_ary on the (N+1)-level objects
https://bugs.ruby-lang.org/issues/5761#change-26052

Author: jonleighton (Jon Leighton)
Status: Closed
Priority: Normal
Assignee: mame (Yusuke Endoh)
Category: core
Target version: 
ruby -v: ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]


$ cat flatten.rb
class Foo
  def respond_to?(name, include_private = true)
    puts "respond_to?(#{name})"
    super
  end

  def method_missing(name, *args)
    puts "method_missing(#{name})"
    super
  end
end

puts "[[Foo.new]].flatten(1)"
p [[Foo.new]].flatten(1)

puts
puts "[[[Foo.new]]].flatten(2)"
p [[[Foo.new]]].flatten(2)

puts
puts "[[[Foo.new]]].flatten(1)"
p [[[Foo.new]]].flatten(1)

$ ruby flatten.rb 
[[Foo.new]].flatten(1)
method_missing(to_ary)
respond_to?(to_ary)
[#<Foo:0x00000001ae41c8>]

[[[Foo.new]]].flatten(2)
method_missing(to_ary)
respond_to?(to_ary)
[#<Foo:0x00000001ae3d90>]

[[[Foo.new]]].flatten(1)
[[#<Foo:0x00000001ae3980>]]

$ ruby -v
ruby 1.9.3p0 (2011-10-30 revision 33570) [x86_64-linux]

Expected behaviour: no method calls are made on the (N+1)-level objects.

For what it's worth, this is the 1.8.7 output:

$ ruby flatten.rb 
[[Foo.new]].flatten(1)
respond_to?(to_ary)
[#<Foo:0x7fef3ebb1888>]

[[[Foo.new]]].flatten(2)
respond_to?(to_ary)
[#<Foo:0x7fef3ebb16a8>]

[[[Foo.new]]].flatten(1)
[[#<Foo:0x7fef3ebb14f0>]]


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