Re: [PATCH v3 03/12] dir: fix off-by-one error in match_pathspec_item
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Sep 13, 2019, 19:05 UTC
- Message-ID
- <xmqq7e6cdnkr.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <20190912221240.18057-4-newren@gmail.com>
Elijah Newren <newren@gmail.com> writes:
> For a pathspec like 'foo/bar' comparing against a path named "foo/", > namelen will be 4, and match[namelen] will be 'b'. The correct location > of the directory separator is namelen-1.
And the reason why name[namelen-1] may not be slash, in which case your new code makes offset 0, is because we need to handle what case? When path is "foo" (not "foo/")? Just makes me wonder why this callee allows the caller(s) to be inconsistent, sometimes including the trailing slash in <name, nemelen> tuple, sometimes not.
Show 5 quoted lines
> The reason the code worked anyway was that the following code immediately > checked whether the first matchlen characters matched (which they do) and > then bailed and return MATCHED_RECURSIVELY anyway since wildmatch doesn't > have the ability to check if "name" can be matched as a directory (or > prefix) against the pathspec.
Nicely spotted and explained.
Show 20 quoted lines
>
> Signed-off-by: Elijah Newren <newren@gmail.com>
> ---
> dir.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/dir.c b/dir.c
> index a9168bed96..bf1a74799e 100644
> --- a/dir.c
> +++ b/dir.c
> @@ -356,8 +356,9 @@ static int match_pathspec_item(const struct index_state *istate,
> /* Perform checks to see if "name" is a super set of the pathspec */
> if (flags & DO_MATCH_SUBMODULE) {
> /* name is a literal prefix of the pathspec */
> + int offset = name[namelen-1] == '/' ? 1 : 0;
> if ((namelen < matchlen) &&
> - (match[namelen] == '/') &&
> + (match[namelen-offset] == '/') &&
> !ps_strncmp(item, match, name, namelen))
> return MATCHED_RECURSIVELY;