worktree: prune linked worktree referencing main worktree path
"git worktree prune" detects when multiple entries are associated with the same path and prunes the duplicates, however, it does not detect when a linked worktree points at the path of the main worktree. Although "git worktree add" disallows creating a new worktree with the same path as the main worktree, such a case can arise outside the control of Git even without the user mucking with .git/worktree/<id>/ administrative files. For instance: $ git clone foo.git $ git -C foo worktree add ../bar $ rm -rf bar $ mv foo bar $ git -C bar worktree list .../bar deadfeeb [master] .../bar deadfeeb [bar] Help the user recover from such corruption by extending "git worktree prune" to also detect when a linked worktree is associated with the path of the main worktree. Reported-by: Jonathan Müller <jonathanmueller.dev@gmail.com> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>