Tools/Scripts/hooks/prepare-commit-msg

#!/usr/bin/env {{ python }}

import os
import subprocess
import sys

LOCATION = '{{ location }}'
SPACING = 8
SCRIPTS = os.path.dirname(os.path.dirname(LOCATION))


def message(source=None, sha=None):
    dirname = None
    commit_message = []

    try:
        for line in subprocess.check_output(
            [os.path.join(SCRIPTS, 'prepare-ChangeLog'), '--no-write', '--only-files', '--delimiters'],
            **(dict(encoding='utf-8') if sys.version_info > (3, 0) else dict())
        ).splitlines():
            if line == '~':
                dirname = None
                continue
            if line.startswith(' ' * SPACING):
                if dirname:
                    line = line.replace('* ', '* {}/'.format(dirname))
                commit_message.append(line[SPACING:])
                continue
            if line.endswith(':'):
                dirname = line.split(':')[0]
                continue

        return '''Need a short description (OOPS!).
Need the bug URL (OOPS!).

Reviewed by NOBODY (OOPS!).

{}
'''.format('\n'.join(commit_message))

    except subprocess.CalledProcessError:
        return ''

def main(file_name=None, source=None, sha=None):
    if source and source != 'commit':
        return 0

    with open(file_name, 'w') as commit_message_file:
        if sha:
            commit_message_file.write(subprocess.check_output(
                ['{{ git }}', 'log', 'HEAD', '-1', '--pretty=format:%B'],
                **(dict(encoding='utf-8') if sys.version_info > (3, 5) else dict())
            ))
        else:
            commit_message_file.write(message(source=source, sha=sha))

        commit_message_file.write('''
# Please populate the above commit message. Lines starting
# with '#' will be ignored

''')
        if sha:
            for line in message(source=source, sha=sha).splitlines():
                commit_message_file.write('# {}\n'.format(line))
            commit_message_file.write('\n')
        for line in subprocess.check_output(
            ['{{ git }}', 'status'],
            **(dict(encoding='utf-8') if sys.version_info > (3, 5) else dict())
        ).splitlines():
            commit_message_file.write('# {}\n'.format(line))

    return 0


if __name__ == '__main__':
    sys.exit(main(*sys.argv[1:]))