Junio C Hamano <gitster@xxxxxxxxx> writes:
> If you know offhand which callers pass neither of the two
> PATHSPEC_PREFER_* bits and remember for what purpose you allowed
> them to do so, please remind me. I'll keep digging in the meantime.
Answering my own questions, here are my findings so far and a
tentative conclusion.
With or without the patch in this thread, parse_pathspec() behaves
the same way for either CWD or FULL if you feed a non-empty
pathspec with at least one positive element. IOW, if a caller feeds
a non-empty pathspec and there is no "negative" element involved, it
does not matter if we feed CWD or FULL.
There are only a handful of callers that pass neither preference
bits to parse_pathspec(). Here are my observations on them that
tells me that most of them are OK if we change them to prefer
either CWD or FULL:
- archive.c::path_exists() feeds a pathspec with a single element
to see if read_tree_recursive() finds any matching paths, to
allow its caller to iterate over the original pathspec and see
if there is a typo (i.e. an element that matches nothing). It
should prefer FULL to match what parse_pathspec_arg(), its
caller, uses.
The caller probably should refrain from passing ones with
negative magic. I.e. "git archive -- t :\!t/perf" errors out
because checking each element independently in the loop means
that ":\!t/perf" is checked alone, triggering "there is nothing
to exclude from".
- blame.c::find_origin() feeds a pathspec with a single element,
which is a path in the history and does so as a literal, hence
no room for "negative" to kick in.
- builtin/check-ignore.c::check_ignore(), when argc==0, does not
call parse_pathspec(). It does not take any magic other than
FROMTOP, so "negative" won't come into the picture.
- builtin/checkout.c::cmd_checkout(), when argc==0, does not call
parse_pathspec(). This codepath will get affected by Linus's
change ("cd t && git checkout :\!perf" would try to check out
everything except t/perf, but what is a reasonable definition of
"everything" in the context of this command). We need to
decide, and I am leaning towards preferring CWD for this case.
- revision.c::setup_revisions() calls parse_pathspec() only when
the caller gave a non-empty pathspec. This pathspec is used for
pruning log traversal (e.g. "only show commits that touch these
paths") and is affected by Linus's change. It should favor
FULL.
- tree-diff.c::try_to_follow_renames() feeds a pathspec with a
single element as a literal, hence no room for "negative" to
kick in.
So, I am tempted to suggest us doing the following:
* Leave a NEEDSWORK comment to archive.c::path_exists() that is
used for checking the validation of pathspec elements. To fix it
properly, we need to be able to skip a negative pathspec to be
passed to this function by the caller, and to do so, we need to
expose a helper from the pathspec API that gets a single string
and returns what magic it has, but that is of lower priority.
* Retire the PATHSPEC_PREFER_CWD bit and replace its use with the
lack of the PATHSPEC_PREFER_FULL bit.
* Keep most of the above callsites that currently do not pass
CWD/FULL as they are, except the ones that should take FULL (see
above).
Comments?