If a user installs this script as .git/hooks/prepare-commit-msg and then
works on an old branch which doesn't have the mklog.py script, trying to
commit will fail with an error like:
environment: /.../gcc/contrib/mklog.py: No such file or directory
This makes it exit cleanly so it's possible to commit.
contrib/ChangeLog:
* prepare-commit-msg: Do nothing if the mklog.py script isn't
present.
This patch introduces a prepare-commit-msg hook that appends a ChangeLog
skeleton to a commit message when the GCC_FORCE_MKLOG environment variable
is set, and a 'git commit-mklog' command set that variable while running
'git commit'.
contrib/ChangeLog:
* prepare-commit-msg: New file.
* gcc-git-customization.sh: Install it. Add commit-mklog alias.
* mklog.py: Add new option -c which appends
to a ChangeLog file.
