Issue #19532 has been updated by usa (Usaku NAKAMURA).
Backport changed from 2.7: UNKNOWN, 3.0: REQUIRED, 3.1: REQUIRED, 3.2: REQUIRED to 2.7:
UNKNOWN, 3.0: REQUIRED, 3.1: DONE, 3.2: REQUIRED
ruby_3_1 0275614ba213dfb6f05743a16f65623bc3b6e274 merged revision(s) 2c8f287.
----------------------------------------
Bug #19532: Handling of 6-byte codepoints in left_adjust_char_head in CESU-8 encoding is
broken
https://bugs.ruby-lang.org/issues/19532#change-103685
* Author: Eregon (Benoit Daloze)
* Status: Open
* Priority: Normal
* ruby -v: ruby 3.2.1 (2023-02-08 revision 31819e82c8) [x86_64-linux]
* Backport: 2.7: UNKNOWN, 3.0: REQUIRED, 3.1: DONE, 3.2: REQUIRED
----------------------------------------
```ruby
irb(main):001:0> "\u{10000}".encode("cesu-8").chop
=> "\xED\xA0\x80"
```
But it should be `""`.
Fix in
https://github.com/ruby/ruby/pull/7510
--
https://bugs.ruby-lang.org/