ref-filter: add --no-contains option to tag/branch/for-each-ref

Change the tag, branch & for-each-ref commands to have a --no-contains
option in addition to their longstanding --contains options.

This allows for finding the last-good rollout tag given a known-bad
<commit>. Given a hypothetically bad commit cf5c7253e0, the git
version to revert to can be found with this hacky two-liner:

    (git tag -l 'v[0-9]*'; git tag -l --contains cf5c7253e0 'v[0-9]*') |
        sort | uniq -c | grep -E '^ *1 ' | awk '{print $2}' | tail -n 10

With this new --no-contains option the same can be achieved with:

    git tag -l --no-contains cf5c7253e0 'v[0-9]*' | sort | tail -n 10

As the filtering machinery is shared between the tag, branch &
for-each-ref commands, implement this for those commands too. A
practical use for this with "branch" is e.g. finding branches which
were branched off between v2.8.0 and v2.10.0:

    git branch --contains v2.8.0 --no-contains v2.10.0

The "describe" command also has a --contains option, but its semantics
are unrelated to what tag/branch/for-each-ref use --contains for. A
--no-contains option for "describe" wouldn't make any sense, other
than being exactly equivalent to not supplying --contains at all,
which would be confusing at best.

Add a --without option to "tag" as an alias for --no-contains, for
consistency with --with and --contains.  The --with option is
undocumented, and possibly the only user of it is
Junio (<xmqqefy71iej.fsf@gitster.mtv.corp.google.com>). But it's
trivial to support, so let's do that.

The additions to the the test suite are inverse copies of the
corresponding --contains tests. With this change --no-contains for
tag, branch & for-each-ref is just as well tested as the existing
--contains option.

In addition to those tests, add a test for "tag" which asserts that
--no-contains won't find tree/blob tags, which is slightly
unintuitive, but consistent with how --contains works & is documented.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/builtin/for-each-ref.c b/builtin/for-each-ref.c
index 1a5ed20f59e..eca365bf89b 100644
--- a/builtin/for-each-ref.c
+++ b/builtin/for-each-ref.c
@@ -9,7 +9,7 @@ static char const * const for_each_ref_usage[] = {
 	N_("git for-each-ref [<options>] [<pattern>]"),
 	N_("git for-each-ref [--points-at <object>]"),
 	N_("git for-each-ref [(--merged | --no-merged) [<commit>]]"),
-	N_("git for-each-ref [--contains [<commit>]]"),
+	N_("git for-each-ref [--contains [<commit>]] [--no-contains [<commit>]]"),
 	NULL
 };
 
@@ -43,6 +43,7 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 		OPT_MERGED(&filter, N_("print only refs that are merged")),
 		OPT_NO_MERGED(&filter, N_("print only refs that are not merged")),
 		OPT_CONTAINS(&filter.with_commit, N_("print only refs which contain the commit")),
+		OPT_NO_CONTAINS(&filter.no_commit, N_("print only refs which don't contain the commit")),
 		OPT_BOOL(0, "ignore-case", &icase, N_("sorting and filtering are case insensitive")),
 		OPT_END(),
 	};