get_worktrees() must return main worktree as first item even on error
This is required by git-worktree.txt, stating that the main worktree is
the first line (especially in --porcelain mode when we can't just change
behavior at will).
There's only one case when get_worktrees() may skip main worktree, when
parse_ref() fails. Update the code so that we keep first item as main
worktree and return something sensible in this case:
- In user-friendly mode, since we're not constraint by anything,
returning "(error)" should do the job (we already show "(detached
HEAD)" which is not machine-friendly). Actually errors should be
printed on stderr by parse_ref() (*)
- In plumbing mode, we do not show neither 'bare', 'detached' or
'branch ...', which is possible by the format description if I read
it right.
Careful readers may realize that when the local variable "head_ref" in
get_main_worktree() is emptied, add_head_info() will do nothing to
wt->head_sha1. But that's ok because head_sha1 is zero-ized in the
previous patch.
(*) Well, it does not. But it's supposed to be a stop gap implementation
until we can reuse refs code to parse "ref: " stuff in HEAD, from
resolve_refs_unsafe(). Now may be the time since refs refactoring is
mostly done.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>