On musl libc, ISO-2022-JP encoder is too eager to switch back to 1 byte encoding, musl's iconv always switch back after every combining character. Comparing glibc and musl's output for this command $ sed q t/t3900/ISO-2022-JP.txt| iconv -f ISO-2022-JP -t utf-8 | iconv -f utf-8 -t ISO-2022-JP | xxd glibc: 00000000: 1b24 4224 4f24 6c24 5224 5b24 551b 2842 .$B$O$l$R$[$U.(B 00000010: 0a . musl: 00000000: 1b24 4224 4f1b 2842 1b24 4224 6c1b 2842 .$B$O.(B.$B$l.(B 00000010: 1b24 4224 521b 2842 1b24 4224 5b1b 2842 .$B$R.(B.$B$[.(B 00000020: 1b24 4224 551b 2842 0a .$B$U.(B. Although musl iconv's output isn't optimal, it's still correct. >From commit 7d509878b8, ("pretty.c: format string with truncate respects logOutputEncoding", 2014-05-21), we're encoding the message to utf-8 first, then format it and convert the message to the actual output encoding on git commit --squash. Thus, t3900 is failing on Linux with musl libc. This problem wasn't specific to musl libc. On Linux with glibc, this problem can be observed by: for encoding in utf-8 iso-8859-1; do # commit using the encoding echo $encoding >file && git add file echo "éñcödèd with $encoding" | iconv -f utf-8 -t $encoding | git -c i18n.commitEncoding=$encoding commit -F - # and then fixup without it echo "$encoding fixed" >file && git add file git commit --fixup HEAD done git rebase -i --autosquash --root Reencode to utf-8 before arranging rebase's todo list. Signed-off-by: Doan Tran Cong Danh <congdanhqx@xxxxxxxxx> --- The code that demonstrate the problem on Linux with glibc is written by Jeff. But I don't know how to attribute him properly. sequencer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sequencer.c b/sequencer.c index 9d5964fd81..69430fe23f 100644 --- a/sequencer.c +++ b/sequencer.c @@ -5169,7 +5169,7 @@ int todo_list_rearrange_squash(struct todo_list *todo_list) *commit_todo_item_at(&commit_todo, item->commit) = item; parse_commit(item->commit); - commit_buffer = get_commit_buffer(item->commit, NULL); + commit_buffer = logmsg_reencode(item->commit, NULL, "UTF-8"); find_commit_subject(commit_buffer, &subject); format_subject(&buf, subject, " "); subject = subjects[i] = strbuf_detach(&buf, &subject_len); -- 2.24.0.rc2.296.geaf699fcc3