Re: [PATCH v2] config.c: split some variables to $GIT_DIR/config.worktree

[Duy Nguyen <pclouds@gmail.com>]

On Fri, Mar 27, 2015 at 5:19 AM, Max Kirillov <max@max630.net> wrote:
> On Thu, Mar 26, 2015 at 07:04:24PM +0700, Nguyễn Thái Ngọc Duy wrote:
>> When you define $GIT_DIR/info/config.worktree, which contains of
>> gitignore-style patterns (*), config variables that match these
>> patterns will be saved in $GIT_DIR/config.worktree instead of
>> $GIT_DIR/config.
>
> Should it rather be in GIT_COMMON_DIR? As far as I
> understand, its meaning is "variables which we allow to use
> per-worktree because we intend to have them different in
> different worktrees, and sure no bad issues
> can happen because this. It is not hardcored in git because
> the list is going to extend, and we'd like to allow older
> versions of git (and other git implementations) to be still
> able to understand newer repositories". So there should be
> no sense to make the list worktree-specific.

I'm not sure if "it" means $GIT_DIR/config.worktree or
$GIT_DIR/info/config.worktree. At this point $GIT_COMMON_DIR is not
involved (i.e. you can still spit config even in a normal repo).
.../info/config.worktree may be shared, I guess.

The "older versions of git (and other git implementations)" raises an
issue with this patch. Older impl just ignore config.worktree. I think
I need to bump core.repositoryformatversion up to avoid that.

> Also, probably the per-worktree variables should be searched
> for in both common config and per-worktree config, and the
> main repository should not have config.worktree, to be able
> to work with implementations which are not aware of the
> whole multiple worktrees feature. And in worktrees, if the
> variable is not defined in config.wortree, the default
> vaalue should come from common config. This though has
> downside that worktree cannot use the more global vlue for
> variable implicitly.

The main worktree may or may not use per-worktree config (it's
technically possible): if we enforce config.worktree on the main
worktree, we don't have to worry about the same variable defined in
both common and per-worktree config. Enforcing may require more work:
imagine the worktree list is updated, some in the common config may
become per-worktree and need to be moved to config.worktree.. If we
allow per-worktree vars in the common config, other worktrees should
ignore them in common config.
-- 
Duy