Open3.popen3 treats string command differently than MRI

[myronmarston]

Given open3_bug.rb:

require 'shellwords'
require 'open3'

command = "ruby -e 'puts ARGV.inspect' #{'a[1:1]'.shellescape}"
puts `#{command}`

Open3.popen3(command) do |_, stdout, stderr|
  puts stdout.read
  puts stderr.read
end

Notice the different output on JRuby compared to MRI 1.8.7 and 2.2 (suggesting that MRI has always behaved this way):

➜ chruby 1.8.7
➜ ruby -v open3_bug.rb
ruby 1.8.7 (2013-12-22 patchlevel 375) [i686-darwin12.5.0]
["a[1:1]"]
["a[1:1]"]

➜ chruby 2.2
➜ ruby -v open3_bug.rb
ruby 2.2.0p0 (2014-12-25 revision 49005) [x86_64-darwin12.0]
["a[1:1]"]
["a[1:1]"]
➜ chruby jruby
➜ ruby -v open3_bug.rb
jruby 1.7.8 (1.9.3p392) 2013-11-14 0ce429e on Java HotSpot(TM) 64-Bit Server VM 1.6.0_65-b14-462-11M4609 [darwin-x86_64]
["a[1:1]"]
["a\\[1:1\\]"]

The escape characters are treated as part of the argument itself when it gets back in ruby on JRuby but not on MRI.

[headius]

Works as expected in JRuby 9000, which has completely reimplemented process spawning.