Re: [PATCH] worktree: teach find_shared_symref to ignore current worktree

["Rubén Justo" <rjusto@gmail.com>]

On 17-ene-2023 15:27:29, Junio C Hamano wrote:

> being solved. Rather, it is unclear what problem you are solving.

Sorry, I didn't explain the motivation well in the message.

First, I'm not sure if "ignore_current_worktree" is correct, maybe needs
to be "prefer_current_worktree".  Having said that, let me use an example.

With...

	$ git worktree add wt1 -b main
	$ git worktree add wt2 -f main

... we get confuse results:

	$ git -C wt1 rebase main main
	Current branch main is up to date.
	$ git -C wt2 rebase main main
	fatal: 'main' is already checked out...

The problem I'm trying to solve is that find_shared_symref() returns the
first matching worktree, and a possible matching "current worktree"
might not be the first matching one.  That's why die_if_checked_out()
dies with "git -C wt2".

find_shared_symref() searches through the list of worktrees that
get_worktrees() composes: first the main worktree and then, as getdir()
returns them, those in .git/worktrees/*.  The search is sequential and
once a match is found, it is returned.  And so die_if_checked_out(),
when asked to "ignore_current_worktree", is going to consider for
"is_current" the worktree which may or may not be the "current" one,
depending on the sequence from get_worktree(), and getdir() ultimately.

If we want to disallow operations on a worktree with a checked out
branch also on another worktree, we need the "ignore_current_worktree".
But, and now I'm more in favor of this, if we prefer to allow the
operation, we need a "prefer_current_worktree", to induce
find_shared_symref() to return the "current" one if it matches, or any
other one that matches.