write_index: optionally allow broken null sha1s

diff --git a/builtin/tag.c b/builtin/tag.c
index f8266888cca97f492dc5b52a992b1dc7cab2909e..af3af3f64935c3f92ed3f85acd44ed2ca2a35b3f 100644 (file)
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -582,7 +582,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
                die(_("%s: cannot lock the ref"), ref.buf);
        if (write_ref_sha1(lock, object, NULL) < 0)
                die(_("%s: cannot update the ref"), ref.buf);
-       if (force && hashcmp(prev, object))
+       if (force && !is_null_sha1(prev) && hashcmp(prev, object))
                printf(_("Updated tag '%s' (was %s)\n"), tag, find_unique_abbrev(prev, DEFAULT_ABBREV));
 
        strbuf_release(&buf);