path.c: add git_common_path() and strbuf_git_common_path()
These are mostly convenient functions to reduce code duplication. Most
of the time, we should be able to get by with git_path() which handles
$GIT_COMMON_DIR internally. However there are a few cases where we need
to construct paths manually, for example some paths from a specific
worktree. These functions will enable that.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
projects / git / commit