Fix --signoff in builtin-commit differently.

Introduce fmt_name() specifically meant for formatting the name and
email pair, to add signed-off-by value.  This reverts parts of
13208572fbe8838fd8835548d7502202d1f7b21d (builtin-commit: fix --signoff)
so that an empty datestamp string given to fmt_ident() by mistake will
error out as before.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index cf0bdc674c..43cfebb0cf 100644
--- a/cache.h
+++ b/cache.h
@@ -444,6 +444,7 @@ enum date_mode parse_date_format(const char *format);
 extern const char *git_author_info(int);
 extern const char *git_committer_info(int);
 extern const char *fmt_ident(const char *name, const char *email, const char *date_str, int);
+extern const char *fmt_name(const char *name, const char *email);
 
 struct checkout {
 	const char *base_dir;