tag: factor out get_tagged_oid()

Add a function for accessing the ID of the object referenced by a tag
safely, i.e. without causing a segfault when encountering a broken tag
where ->tagged is NULL.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/tag.h b/tag.h
index 03265fbfe2..3ce8e72192 100644
--- a/tag.h
+++ b/tag.h
@@ -19,5 +19,6 @@ struct object *deref_tag(struct repository *r, struct object *, const char *, in
 struct object *deref_tag_noverify(struct object *);
 int gpg_verify_tag(const struct object_id *oid,
 		   const char *name_to_report, unsigned flags);
+struct object_id *get_tagged_oid(struct tag *tag);
 
 #endif /* TAG_H */