Bug #7168: File.join trips over string encodings

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 1.9.3p125 (2012-02-16 revision 34643) [x86_64-darwin11.3.0]

[aparker42 (Andrew Parker)]

It seems like File.join is unable to handle string encodings that contain null bytes even though the string is properly encoded. This causes it to be unable to process inputs when the filenames on the system are encoded in this manner.

From an irb session:

1.9.3p125 :013 > File.join("a".encode("UTF-16LE")).encoding
 => #<Encoding:UTF-16LE> 
1.9.3p125 :014 > File.join("a".encode("UTF-16LE"), "".encode("UTF-16LE"))
ArgumentError: string contains null byte
from (irb):14:in `join'
from (irb):14
from /Users/andy/.rvm/rubies/ruby-1.9.3-p125/bin/irb:16:in `<main>'

I would expect the second command in that session to return "a/" just like File.join("a", "") does, but with the UTF-16LE encoding.

See https://groups.google.com/forum/?hl=en&fromgroups=#!topic/puppet-dev/C1YODJxd9Ws for where this came from.

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r37207.
Andrew, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

file.c: ASCII-compatible

• file.c (rb_file_join): path names must be ASCII-compatible.
  [ruby-core:48012] [Bug #7168]

[aparker42 (Andrew Parker)]

I don't see how that patch fixes the issue to achieve the behavior that I expected. It looks like it will just raise an explicit error instead of the ArgumentError.

For systems that have multi-byte, fixed-size encodings how is this supposed to work?

[nobu (Nobuyoshi Nakada)]

Use UTF-8.

I don't think Darwin uses wide chars for file systems, though.

[aparker42 (Andrew Parker)]

You are right that Darwin doesn't have this problem, as far as I know. As I pointed out the problem was originally found on Windows, where the filesystem uses UTF-16.

Why is the behavior that I expected (that File.join can work with any String) wrong?