Ruby

Hi Nakada-san:

D:\> ruby -v ruby 2.2.3p147 (2015-07-04 revision 51143) [x64-mswin64_120] D:\> ruby test.rb test.rb:8:in `==': stack level too deep (SystemStackError) from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:8:in `==' ... 2574 levels... from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:8:in `==' from test.rb:17:in `<main>' 

It seems to be a problem specific to Windows. The test suite passes (IIRC)

Should the result not be false instead?
These two instances each have a different @friend and it cannot be determined if they are equal so "false" seems a much safer answer.

Also, this seems inconsistent to how Comparable#== treat such cases:

class Something attr_accessor :friend def initialize(friend) self.friend = friend end include Comparable def <=>(other) friend <=> other end end a = Something.new([]) b = Something.new([a]) a.friend = [b] p a == b # false (and not true like above!) 

my version is "ruby 2.3.0dev (2015-07-21 trunk 51319) [x86_64-linux]"

and it does return true for me too

#1448 and the specs in
https://github.com/ruby/rubyspec/blob/master/core/array/shared/eql.rb
convinced me this is desirable behavior.