commit 71fa8d22126c52167cb8579d5d194a0fbee4dc8e
author Torsten Bögershausen <tboegi@web.de> Fri May 31 21:31:56 2024 +0200
committer Junio C Hamano <gitster@pobox.com> Fri May 31 13:13:40 2024 -0700
tree d19ea47eb3e50227092572cf9aa38e2d40822a11
parent 61a22ddaf0626111193a17ac12f366bd6d167dff

macOS: ls-files path fails if path of workdir is NFD

Under macOS, `git ls-files path` does not work (gives an error)
if the absolute 'path' contains characters in NFD (decomposed).
This happens when core.precomposeunicode is true, which is the
most common case. The bug report says:

$ cd somewhere          # some safe place, /tmp or ~/tmp etc.
$ mkdir $'u\xcc\x88'    # ü in NFD
$ cd ü                  # or cd $'u\xcc\x88' or cd $'\xc3\xbc'
$ git init
$ git ls-files $'/somewhere/u\xcc\x88'   # NFD
  fatal: /somewhere/ü: '/somewhere/ü' is outside repository at '/somewhere/ü'
$ git ls-files $'/somewhere/\xc3\xbc'    # NFC
(the same error as above)

In the 'fatal:' error message, there are three ü;
the 1st and 2nd are in NFC, the 3rd is in NFD.

Add test cases that follows the bug report, with the simplification
that the 'ü' is replaced by an 'ä', which is already used as NFD and
NFC in t3910.

The solution is to add a call to precompose_string_if_needed()
to this code in setup.c :
`work_tree = precompose_string_if_needed(get_git_work_tree());`

There is, however, a limitation with this very usage of Git:
The (repo) local .gitconfig file is not used, only the global
"core.precomposeunicode" is taken into account, if it is set (or not).
To set it to true is a good recommendation anyway, and here is the
analyzes from Jun T :

The problem is the_repository->config->hash_initialized
is set to 1 before the_repository->commondir is set to ".git".
Due to this, .git/config is never read, and precomposed_unicode
is never set to 1 (remains -1).

run_builtin() {
    setup_git_directory() {
        strbuf_getcwd() {   # setup.c:1542
            precompose_{strbuf,string}_if_needed() {
                # precomposed_unicode is still -1
                git_congig_get_bool("core.precomposeunicode") {
                    git_config_check_init() {
                        repo_read_config() {
                            git_config_init() {
                                # !!!
                                the_repository->config->hash_initialized=1
                                # !!!
                            }
                            # does not read .git/config since
                            # the_repository->commondir is still NULL
                        }
                    }
                }
                returns without converting to NFC
            }
            returns cwd in NFD
        }

        setup_discovered_git_dir() {
            set_git_work_tree(".") {
                repo_set_worktree() {
                    # this function indirectly calls strbuf_getcwd()
                    # --> precompose_{strbuf,string}_if_needed() -->
                    # {git,repo}_config_get_bool("core.precomposeunicode"),
                    # but does not try to read .git/config since
                    # the_repository->config->hash_initialized
                    # is already set to 1 above. And it will not read
                    # .git/config even if hash_initialized is 0
                    # since the_repository->commondir is still NULL.

                    the_repository->worktree = NFD
                }
            }
        }

        setup_git_env() {
            repo_setup_gitdir() {
                repo_set_commondir() {
                    # finally commondir is set here
                    the_repository->commondir = ".git"
                }
            }
        }

    } // END setup_git_directory

Reported-by: Jun T <takimoto-j@kba.biglobe.ne.jp>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>