commit: print "Date" line when the user has set date

When we make a commit and the author is not the same as the
committer (e.g., because you used "-c $commit" or
"--author=$somebody"), we print the author's name and email
in both the commit-message template and as part of the
commit summary. This is a safety check to give the user a
chance to confirm that we are doing what they expect.

This patch brings the same safety for the "date" field,
which may be set by "-c" or by using "--date".  Note that we
explicitly do not set it for $GIT_AUTHOR_DATE, as it is
probably not of interest when "git commit" is being fed its
parameters by a script.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/builtin/commit.c b/builtin/commit.c
index 728cc9bbfc..a25661f343 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -592,6 +592,11 @@ static void split_ident_or_die(struct ident_split *id, const struct strbuf *buf)
 		die(_("Malformed ident string: '%s'"), buf->buf);
 }
 
+static int author_date_is_interesting(void)
+{
+	return author_message || force_date;
+}
+
 static int prepare_to_commit(const char *index_file, const char *prefix,
 			     struct commit *current_head,
 			     struct wt_status *s,
@@ -805,6 +810,13 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
 				(int)(ai.name_end - ai.name_begin), ai.name_begin,
 				(int)(ai.mail_end - ai.mail_begin), ai.mail_begin);
 
+		if (author_date_is_interesting())
+			status_printf_ln(s, GIT_COLOR_NORMAL,
+				_("%s"
+				"Date:      %s"),
+				ident_shown++ ? "" : "\n",
+				show_ident_date(&ai, DATE_NORMAL));
+
 		if (!committer_ident_sufficiently_given())
 			status_printf_ln(s, GIT_COLOR_NORMAL,
 				_("%s"
@@ -1355,6 +1367,13 @@ static void print_summary(const char *prefix, const unsigned char *sha1,
 		strbuf_addstr(&format, "\n Author: ");
 		strbuf_addbuf_percentquote(&format, &author_ident);
 	}
+	if (author_date_is_interesting()) {
+		struct strbuf date = STRBUF_INIT;
+		format_commit_message(commit, "%ad", &date, &pctx);
+		strbuf_addstr(&format, "\n Date: ");
+		strbuf_addbuf_percentquote(&format, &date);
+		strbuf_release(&date);
+	}
 	if (!committer_ident_sufficiently_given()) {
 		strbuf_addstr(&format, "\n Committer: ");
 		strbuf_addbuf_percentquote(&format, &committer_ident);