Bug #20052: reline behaves oddly with redirect (non tty)

• Status: Third Party's Issue
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.0dev (2023-12-09 master 1cbe114d1c) [x86_64-linux]
• Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN

[mtasaka (Mamoru TASAKA)]

Forwarded from cucumber/aruba testsute issue https://github.com/cucumber/aruba/issues/910

Looks line reline behaves oddly with redirect (non tty)

With ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux] and Readline:

$ echo 'foo' | ruby -e 'require "readline"; puts Readline.readline(">")' > bar.log ; cat bar.log 
>foo
foo

With ruby 3.3.0dev (2023-12-09 master 1cbe114d1c) [x86_64-linux] and Reline:

$ echo 'foo' | ruby -e 'require "reline"; puts Reline.readline(">")' > bar.log ; cat bar.log 
>>>f>f>fo>fo>foo>foofoo

[rubyFeedback (robert heiler)]

Interesting. It seems to do some additional buffering? If it behaves differently to readline then this may be a bug in behaviour; at the least if it is not a bug then the user may want to be able to get the readline-behaviour and perhaps an option to toggle between these two (though I think the Readline behaviour makes more sense, so I assume this may be a bug indeed.)

[matijsvanzuijlen (Matijs van Zuijlen)]

(Aruba maintainer here) Note that the reline behavior is the same on Ruby 3.2.2, so it doesn't seem to be caused by any change in Ruby itself. It just manifested for Aruba because readline is gone in 3.3.0dev.

[Eregon (Benoit Daloze)]

It may be better to report this at https://github.com/ruby/reline

[mtasaka (Mamoru TASAKA)]

Forwarded: https://github.com/ruby/reline/issues/616

[vo.x (Vit Ondruch)]

Since there was no upstream response, I'll ask here if somebody can look into the issue. Workarounds such as "install readline-ext" are suboptimal and against changes done in Ruby 3.3 on purpose.

[hsbt (Hiroshi SHIBATA)]

• Status changed from Open to Third Party's Issue