Backport #8153
closed
Problems with Enumerable#zip caused by overriding Object#respond_to?
Description
If I override Object#respond_to? under Ruby 2.0.0, Enumerable#zip begins to misbehave. Here is the code and output in Ruby 2.0.0:
2.0.0p0 :001 > RUBY_VERSION
=> "2.0.0"
2.0.0p0 :002 > class Object
2.0.0p0 :003?> alias :_respond_to? :respond_to?
2.0.0p0 :004?> def respond_to?(*a)
2.0.0p0 :005?> _respond_to?(*a)
2.0.0p0 :006?> end
2.0.0p0 :007?> end
=> nil
2.0.0p0 :008 > [1,2,3].zip((1..3).each)
=> [[1, nil], [2, nil], [3, nil]]
Should be: [[1, 1], [2, 2], [3, 3]]
Here is the output I was expecting, generated in Ruby 1.9.3 -- ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-darwin12.2.0]:
1.9.3p392 :001 > RUBY_VERSION
=> "1.9.3"
1.9.3p392 :002 > class Object
1.9.3p392 :003?> alias :_respond_to? :respond_to?
1.9.3p392 :004?> def respond_to?(*a)
1.9.3p392 :005?> _respond_to?(*a)
1.9.3p392 :006?> end
1.9.3p392 :007?> end
=> nil
1.9.3p392 :008 > [1,2,3].zip((1..3).each)
=> [[1, 1], [2, 2], [3, 3]]
1.9.3p392 :009 >
I'm not certain if this is the only method which is interfered with, but it's how I determined an issue was present initially.
For copy and paste convenience:
class Object
alias :_respond_to? :respond_to?
def respond_to?(*a)
_respond_to?(*a)
end
end
[1,2,3].zip((1..3).each)
FWIW, the same behaviour occurs if using a prepend-ed module and super:
module RespondToBug
def respond_to?(*a)
super
end
end
class Object
prepend RespondToBug
end
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