Bug #20883: sprintf with binary strings has incorrect coderange

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: ruby 3.3.5 (2024-09-03 revision ef084cc8f4) [x86_64-linux]
• Backport: 3.1: DONTNEED, 3.2: DONE, 3.3: REQUIRED

[jhawthorn (John Hawthorn)]

In 9dc6065 we stopped updating the coderange when the encoding became ENCINDEX_ASCII_8BIT. Though ASCII-8BIT (binary) can't ever have a broken coderange, it does need to distinguish between 7bit and valid.

puts ("%s" % "\xe2".b).ascii_only?
# => false from Ruby 2.1 to 3.1
# => true (incorrect) on Ruby 3.2 and 3.3
# => false again on HEAD

This was fixed in master as part of #20189, which clears the coderange in more cases of rb_str_resize which happens to fix this, but we shouldn't rely on it.

https://github.com/ruby/ruby/pull/12029

[jhawthorn (John Hawthorn)]

• Status changed from Open to Closed

Applied in changeset git|1f6dd9071c7994dd639d2e1cf2fe04e944173f17.

---

Fix update_coderange for binary strings

Although a binary (aka ASCII-8BIT) string will never have a broken
coderange, it still has to differentiate between "valid" and "7bit".

On Ruby 3.4/trunk this problem is masked because we now clear the
coderange more agressively in rb_str_resize, and we happened to always
be strinking this string, but we should not assume that.

On Ruby 3.3 this created strings where ascii_only? was true in cases
it shouldn't be as well as other problems.

Fixes [Bug #20883]

Co-authored-by: Daniel Colson [e-mail]
Co-authored-by: Matthew Draper [e-mail]

[jhawthorn (John Hawthorn)]

I opened two backport PRs. I marked 3.2 and 3.3 as REQUIRED for backport, but the bug is fairly mild if the branch maintainers would rather skip it.

3.2: https://github.com/ruby/ruby/pull/12041
3.3: https://github.com/ruby/ruby/pull/12040

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 3.1: DONTNEED, 3.2: REQUIRED, 3.3: REQUIRED to 3.1: DONTNEED, 3.2: DONE, 3.3: REQUIRED

ruby_3_2 9bcc5c5fd9e8e4d15040eec6850b49d860eba621.

[nagachika (Tomoyuki Chikanaga)]

Merged the PR for ruby_3_2 at 9bcc5c5fd9e8e4d15040eec6850b49d860eba621. Thank you for the PRs.