describe: teach --match to accept multiple patterns

Teach `--match` to be accepted multiple times, accumulating a list of
patterns to match into a string list. Each pattern is inclusive, such
that a tag need only match one of the provided patterns to be
considered for matching.

This extension is useful as it enables more flexibility in what tags
match, and may avoid the need to run the describe command multiple
times to get the same result.

Add tests and update the documentation for this change.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/Documentation/git-describe.txt b/Documentation/git-describe.txt
index e4ac448..7ad41e2 100644
--- a/Documentation/git-describe.txt
+++ b/Documentation/git-describe.txt
@@ -83,7 +83,10 @@ OPTIONS
 --match <pattern>::
 	Only consider tags matching the given `glob(7)` pattern,
 	excluding the "refs/tags/" prefix.  This can be used to avoid
-	leaking private tags from the repository.
+	leaking private tags from the repository. If given multiple times, a
+	list of patterns will be accumulated, and tags matching any of the
+	patterns will be considered. Use `--no-match` to clear and reset the
+	list of patterns.
 
 --always::
 	Show uniquely abbreviated commit object as fallback.