RE: Bug report - Can create worktrees from bare repo / such worktrees can fool is_bare_repository()

On December 19, 2021 3:47 PM, Sean Allred wrote:

To: Eric Sunshine <redacted>
Cc: git@vger.kernel.org
Subject: Re: Bug report - Can create worktrees from bare repo / such
worktrees can fool is_bare_repository()

quoted

However, you missed the step (discussed in [1]) in which it is your
responsibility to move the `core.bare=true` setting from
git.git/config to git.git/worktree.config manually after setting
`extensions.worktreeconfig=true`.

Ahh, that makes sense!  I did notice the `core.bare` setting being respected
in source and figured this had a part to play (which is why I included git-config
output).

I think then that I was overzealous in trying to MWE-ify the issue: as I noted, I
found this issue when I was trying to perform a sparse-checkout within the
worktree.  To memory (I don't have my work system at the moment and
don't have its `history`), I think it went something like this:

    git worktree add --no-checkout ../next && cd ../next
    git sparse-checkout init --cone # auto-created a worktree config
    git sparse-checkout set t

I think either the git-sparse-checkout-set command (or the git-checkout I ran
after) would fail complaining that I was not in a worktree.  Based on the
above, it sounds like `init` is creating the worktree-specific config, but is not
overriding `core.bare` in that config.  Would a patch to take this step this
automatically be well-received?  I see two options for when to set
`core.bare=false` in worktree-specific config:

  1. At git-worktree-add: This is probably the earliest time which
     makes sense, but may be over-reach.  I'm not up-to-speed on how
     worktree-specific configs are generally considered on this list.
     If I were implementing a workaround, though, this is probably
     where I'd make it.

  2. At git-sparse-checkout-init: This is where the problem begins to
     have an effect, so this might also make sense.

I'm glad to learn about bare repositories + worktrees being a supported use-
case :-)

Fair enough, but what about the comparison code where is_bare_repository_cfg is compared with 1 (it is a boolean and sometimes set to -1). This would not generally pass a code review.
-Randall