Hash#select! inconsistency with MRI when yielding only one argument

[robin850]

Hello,

There's a tiny behavioral difference between MRI and JRuby regarding the Hash#select! method when there's only one argument passed to the method's block:

>> h = {a: :b}

>> RUBY_ENGINE
=> "ruby"
>> h.select! { |k| p k }
:a

>> RUBY_ENGINE
=> "jruby"
>> h.select! { |k| p k }
[:a, :b]

The problem seems to be in keep_ifCommon ; I tried to write a fix but I haven't been able to.

Have a nice day!

[kares]

you mean JRuby 1.7.x right? ... there's been a similar issue with take_while

[robin850]

@kares : Actually I did not test with 1.7, just with JRuby 9000

[kares]

quick test - 1.7.x behaves fine (compatibly with MRI 1.9.3) thus marking as 9K :

jruby-1.7.20 :001 > h = {a: :b}
 => {:a=>:b} 
jruby-1.7.20 :002 > h.select! { |k| p k }
:a

[enebo]

This one is non-trivial to fix atm but it is pretty important so we will target this (along with several other block parameter bugs for first point release after release.

[enebo]

yieldSpecific with two args to a proc which receives one arg is broken atm but I changed these all to yieldArray. I would try and fix yieldSpecific but we have a much larger task for blocks and it will get handled then.

[robin850]

Thanks for fixing this !