Re: [PATCH] sha1-name.c: for ":/", find detached HEAD commits

>
> This patch broadens the set of commits matched by ":/" pathspecs to
> include commits reachable from HEAD but not any named ref. This avoids
> surprising behavior when working with a detached HEAD and trying to
> refer to a commit that was recently created and only exists within the
> detached state.

>
> Signed-off-by: William Chargin <wchargin@gmail.com>
> Based-on-patch-by: Jeff King <peff@peff.net>
> ---
>  Documentation/revisions.txt   | 10 +++++-----
>  sha1-name.c                   |  1 +
>  t/t4208-log-magic-pathspec.sh | 14 ++++++++++++++
>  3 files changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/revisions.txt b/Documentation/revisions.txt
> index 7d1bd4409..aa56907fd 100644
> --- a/Documentation/revisions.txt
> +++ b/Documentation/revisions.txt
> @@ -181,11 +181,11 @@ existing tag object.
>    the '<rev>' before '{caret}'.
>
>  ':/<text>', e.g. ':/fix nasty bug'::
> -  A colon, followed by a slash, followed by a text, names
> -  a commit whose commit message matches the specified regular expression.
> -  This name returns the youngest matching commit which is
> -  reachable from any ref. The regular expression can match any part of the
> -  commit message. To match messages starting with a string, one can use
> +  A colon, followed by a slash, followed by a text, names a commit whose
> +  commit message matches the specified regular expression. This name
> +  returns the youngest matching commit which is reachable from any ref
> +  or from HEAD. The regular expression can match any part of the commit
> +  message. To match messages starting with a string, one can use
>    e.g. ':/^foo'. The special sequence ':/!' is reserved for modifiers to what
>    is matched. ':/!-foo' performs a negative match, while ':/!!foo' matches a
>    literal '!' character, followed by 'foo'. Any other sequence beginning with
> diff --git a/sha1-name.c b/sha1-name.c
> index 60d9ef3c7..641ca12f9 100644
> --- a/sha1-name.c
> +++ b/sha1-name.c
> @@ -1650,6 +1650,7 @@ static int get_oid_with_context_1(const char *name,
>                         struct commit_list *list = NULL;
>
>                         for_each_ref(handle_one_ref, &list);
> +                       head_ref(handle_one_ref, &list);

>                         commit_list_sort_by_date(&list);
>                         return get_oid_oneline(name + 2, oid, list);
>                 }
> diff --git a/t/t4208-log-magic-pathspec.sh b/t/t4208-log-magic-pathspec.sh
> index 62f335b2d..41b9f3eba 100755
> --- a/t/t4208-log-magic-pathspec.sh
> +++ b/t/t4208-log-magic-pathspec.sh
> @@ -25,6 +25,20 @@ test_expect_success '"git log :/a -- " should not be ambiguous' '
>         git log :/a --
>  '
>
> +test_expect_success '"git log :/detached -- " should find a commit only in HEAD' '
> +       test_when_finished "git checkout master" &&
> +       git checkout --detach &&
> +       test_tick &&
> +       git commit --allow-empty -m detached &&
> +       test_tick &&
> +       git commit --allow-empty -m something-else &&
> +       git log :/detached --
> +'
> +
> +test_expect_success '"git log :/detached -- " should not find an orphaned commit' '
> +       test_must_fail git log :/detached --
> +'
> +
>  test_expect_success '"git log -- :/a" should not be ambiguous' '
>         git log -- :/a
>  '
> --
> 2.18.0.130.g61d0c9dcf
>