Change unpack_trees' 'reset' flag into an enum

Traditionally, unpack_trees_options->reset was used to signal that it
was okay to delete any untracked files in the way.  This was used by
`git read-tree --reset`, but then started appearing in other places as
well.  However, many of the other uses should not be deleting untracked
files in the way.  Change this value to an enum so that a value of 1
(i.e. "true") can be split into two:
   UNPACK_RESET_PROTECT_UNTRACKED,
   UNPACK_RESET_OVERWRITE_UNTRACKED
In order to catch accidental misuses (i.e. where folks call it the way
they traditionally used to), define the special enum value of
   UNPACK_RESET_INVALID = 1
which will trigger a BUG().

Modify existing callers so that
   read-tree --reset
   reset --hard
   checkout --force
continue using the UNPACK_RESET_OVERWRITE_UNTRACKED logic, while other
callers, including
   am
   checkout without --force
   stash  (though currently dead code; reset always had a value of 0)
   numerous callers from rebase/sequencer to reset_head()
will use the new UNPACK_RESET_PROTECT_UNTRACKED value.

Also, note that it has been reported that 'git checkout <treeish>
<pathspec>' currently also allows overwriting untracked files[1].  That
case should also be fixed, but it does not use unpack_trees() and thus
is outside the scope of the current changes.

[1] https://lore.kernel.org/git/15dad590-087e-5a48-9238-5d2826950506@gmail.com/

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Elijah Newren
2021-09-27 16:33:44 +00:00
committed by Junio C Hamano
parent 1b5f37334a
commit 480d3d6bf9
9 changed files with 39 additions and 16 deletions

View File

@ -646,9 +646,10 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
opts.head_idx = -1;
opts.update = worktree;
opts.skip_unmerged = !worktree;
opts.reset = 1;
opts.reset = o->force ? UNPACK_RESET_OVERWRITE_UNTRACKED :
UNPACK_RESET_PROTECT_UNTRACKED;
opts.preserve_ignored = (!o->force && !o->overwrite_ignore);
opts.merge = 1;
opts.preserve_ignored = 0;
opts.fn = oneway_merge;
opts.verbose_update = o->show_progress;
opts.src_index = &the_index;