[PATCH V4] git on Mac OS and precomposed unicode

Changes since V3:

- Be much more defensive:
  Do not set core.precomposedunicode=true, even if the file system
  probing indicates that it could be true.
  (but we don't say that it should be true).
  This is to keep better backward compatibility within git.
  The user needs to manually enable the precomposition.
  However, the .git/config indicates that we have a new
  configuration variable, and will encourage people to use it.

- compat/precomposed_utf8.c: 
    - re-order #includes
    - Added some empty lines to make code easier to read. 
    - Small fixes (xmalloc, errno handling)

- Make function names more consistent by renaming these functions:
    argv_precompose() -> precompose_argv()
    str_precompose() -> precompose_str()
- Improved the commit message

Torsten Bögershausen (1):
  git on Mac OS and precomposed unicode

 Documentation/config.txt     |    9 ++
 Makefile                     |    3 +
 builtin/init-db.c            |    2 +
 compat/precomposed_utf8.c    |  208 ++++++++++++++++++++++++++++++++++++++++++
 compat/precomposed_utf8.h    |   30 ++++++
 git-compat-util.h            |    9 ++
 git.c                        |    1 +
 t/t3910-mac-os-precompose.sh |  117 +++++++++++++++++++++++
 8 files changed, 379 insertions(+), 0 deletions(-)
 create mode 100644 compat/precomposed_utf8.c
 create mode 100644 compat/precomposed_utf8.h
 create mode 100755 t/t3910-mac-os-precompose.sh