Subject: [PATCH v2 0/3] Linux with musl libc improvement

From: Doan Tran Cong Danh <[email-masked]>
Date: Fri, 1 Nov 2019 15:25:08 +0700

This series of patch tries to ease the life of musl libc user
and clear those last failure on Linux with musl libc.

The second patch is a complete rewrite.

Doan Tran Cong Danh (3):
  t0028: eliminate non-standard usage of printf
  configure.ac: define ICONV_OMITS_BOM if necessary
  sequencer: reencode to utf-8 before arrange rebase's todo list

 configure.ac                     | 49 ++++++++++++++++++++++++++++++++
 sequencer.c                      |  2 +-
 t/t0028-working-tree-encoding.sh |  4 +--
 3 files changed, 52 insertions(+), 3 deletions(-)

Range-diff against v1:
1:  840c40cea1 ! 1:  8b30028425 t0028: eliminate non-standard usage of printf
    @@ Commit message
            one, two, or three-digit octal number, shall be written as a byte
            with the numeric value specified by the octal number.
     
    -    printf '\xfe\xff' in an extension of some libc.
    +    printf '\xfe\xff' in an extension of some shell.
    +    Dash, a popular yet simple shell, do not implement this extension.
     
    -    With dash:
    -    $ printf '\xfe\xff' | xxd
    -    00000000: 5c78 6665 5c78 6666                      \xfe\xff
    +    This wasn't caught by most people running the tests, even though
    +    common shells like dash don't handle hex escapes, because their
    +    systems don't trigger the NO_UTF16_BOM prereq. But systems with musl
    +    libc do; when combined with dash, the test fails.
     
    -    Correct its usage.
    +    Correct it.
     
         Signed-off-by: Doan Tran Cong Danh <[email-masked]>
    -    Despite that dash's printf doesn't accept \x escape sequence.
    -
    -    My glibc box (with sh linked to dash) can run the test just fine.
    -    But my musl box couldn't run the test, (because the header).
     
      ## t/t0028-working-tree-encoding.sh ##
     @@ t/t0028-working-tree-encoding.sh: test_lazy_prereq NO_UTF32_BOM '
2:  4a28ee7ef6 < -:  ---------- configure.ac: define ICONV_OMITS_BOM if necessary
-:  ---------- > 2:  7c2c6f0603 configure.ac: define ICONV_OMITS_BOM if necessary
3:  c8da3990e5 ! 3:  b7927b2723 sequencer: reencode to utf-8 before arrange rebase's todo list
    @@ Commit message
     
         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 <[email-masked]>
    -    The todo list shown to user has already been reencoded by sequencer_make_script,
    -    without this patch it looks like this:
    -
    -    $ head -3 .git/rebase-merge/git-rebase-todo | xxd
    -    00000000: 7069 636b 2065 6633 3961 3033 201b 2442  pick ef39a03 .$B
    -    00000010: 244f 1b28 421b 2442 246c 1b28 421b 2442  $O.(B.$B$l.(B.$B
    -    00000020: 2452 1b28 421b 2442 245b 1b28 421b 2442  $R.(B.$B$[.(B.$B
    -    00000030: 2455 1b28 420a 7069 636b 2062 3832 3931  $U.(B.pick b8291
    -    00000040: 3336 2073 7175 6173 6821 201b 2442 244f  36 squash! .$B$O
    -    00000050: 1b28 421b 2442 246c 1b28 421b 2442 2452  .(B.$B$l.(B.$B$R
    -    00000060: 1b28 421b 2442 245b 1b28 421b 2442 2455  .(B.$B$[.(B.$B$U
    -    00000070: 1b28 420a 7069 636b 2062 3532 3132 6437  .(B.pick b5212d7
    -    00000080: 2069 6e74 6572 6d65 6469 6174 6520 636f   intermediate co
    -    00000090: 6d6d 6974 0a                             mmit.
     
      ## sequencer.c ##
     @@ sequencer.c: int todo_list_rearrange_squash(struct todo_list *todo_list)
-- 
2.24.0.rc2.296.geaf699fcc3