Bug #10748: Array#flatten(N) calls to_ary on the (N+1)-level objects

• Status: Closed
• Assignee: mame (Yusuke Endoh)
• Target version: -
• ruby -v: ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-darwin13.0]
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN

[ryannevell (Ryan Nevell)]

$ 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)
respond_to?(to_ary)
[#<Foo:0x007fb959177f90>]

[[[Foo.new]]].flatten(2)
respond_to?(to_ary)
[#<Foo:0x007fb959177d10>]

[[[Foo.new]]].flatten(1)
[[#<Foo:0x007fb959177ab8>]]

$ ruby -v
ruby 2.1.2p95 (2014-05-08 revision 45877) [x86_64-darwin13.0]

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

This is the same as bug #5761, but has resurfaced in a later version.

[ryannevell (Ryan Nevell)]

• Copied from Bug #5761: Array#flatten(N) calls to_ary on the (N+1)-level objects added

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

Applied in changeset r49400.

---

array.c: reduce to_ary call

• array.c (flatten): no need to call to_ary method on elements
  beyond the given level. [ruby-core:67637] [Bug #10748]

[wanabe (_ wanabe)]

• Backport set to 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN