Issue #20305 has been updated by fablestales (Fable Tales). I added a failing test to reproduce this issue in this PR: https://github.com/ruby/ruby/pull/10103 ---------------------------------------- Bug #20305: commit 1d2d25dcadda0764f303183ac091d0c87b432566 breaks grapheme_clusters https://bugs.ruby-lang.org/issues/20305#change-107004 * Author: fablestales (Fable Tales) * Status: Open * Backport: 3.0: UNKNOWN, 3.1: UNKNOWN, 3.2: UNKNOWN, 3.3: UNKNOWN ---------------------------------------- given a script: ``` #script.rb p "안녕".byteslice(0, 4).grapheme_clusters ``` The commit 1d2d25dcadda0764f303183ac091d0c87b432566 (https://github.com/ruby/ruby/commit/1d2d25dcadda0764f303183ac091d0c87b432566) breaks the grapheme_clusters method on a byte slice ``` (commit 1d2d25dcadda0764f303183ac091d0c87b432566) ((HEAD detached at 1d2d25dcad)) $ ./ruby --disable=gems script.rb ["안", "\xEB"] ((HEAD detached at 1d2d25dcad)) $ git checkout HEAD^ (114e71d06280f9c57b9859ee4405ae89a989ddb6) ((HEAD detached at 114e71d062)) $ make -j ... ((HEAD detached at 114e71d062)) $ ./ruby --disable=gems script.rb ["안"] ((HEAD detached at 114e71d062)) $ cat script.rb p "안녕".byteslice(0, 4).grapheme_clusters ``` the expected result here is almost certainly the latter output, and not the former. -- https://bugs.ruby-lang.org/