show_date(): rename the "relative" parameter to "mode"

Now, show_date() can print three different kinds of dates: normal,
relative and short (%Y-%m-%s) dates.

To achieve this, the "int relative" was changed to "enum date_mode
mode", which has three states: DATE_NORMAL, DATE_RELATIVE and
DATE_SHORT.

Since existing users of show_date() only call it with relative_date
being either 0 or 1, and DATE_NORMAL and DATE_RELATIVE having these
values, no behaviour is changed.
Signed-off-by: NJohannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: NJunio C Hamano <junkio@cox.net>

cache.h

@@ -315,7 +315,8 @@ extern void *read_object_with_reference(const unsigned char *sha1,
 					unsigned long *size,
 					unsigned char *sha1_ret);
 
-const char *show_date(unsigned long time, int timezone, int relative);
+enum date_mode { DATE_NORMAL = 0, DATE_RELATIVE, DATE_SHORT };
+const char *show_date(unsigned long time, int timezone, enum date_mode mode);
 const char *show_rfc2822_date(unsigned long time, int timezone);
 int parse_date(const char *date, char *buf, int bufsize);
 void datestamp(char *buf, int bufsize);

date.c

@@ -55,12 +55,12 @@ static struct tm *time_to_tm(unsigned long time, int tz)
 	return gmtime(&t);
 }
 
-const char *show_date(unsigned long time, int tz, int relative)
+const char *show_date(unsigned long time, int tz, enum date_mode mode)
 {
 	struct tm *tm;
 	static char timebuf[200];
 
-	if (relative) {
+	if (mode == DATE_RELATIVE) {
 		unsigned long diff;
 		struct timeval now;
 		gettimeofday(&now, NULL);
@@ -105,12 +105,16 @@ const char *show_date(unsigned long time, int tz, int relative)
 	tm = time_to_tm(time, tz);
 	if (!tm)
 		return NULL;
-	sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+05d",
-		weekday_names[tm->tm_wday],
-		month_names[tm->tm_mon],
-		tm->tm_mday,
-		tm->tm_hour, tm->tm_min, tm->tm_sec,
-		tm->tm_year + 1900, tz);
+	if (mode == DATE_SHORT)
+		sprintf(timebuf, "%04d-%02d-%02d", tm->tm_year + 1900,
+				tm->tm_mon + 1, tm->tm_mday);
+	else
+		sprintf(timebuf, "%.3s %.3s %d %02d:%02d:%02d %d %+05d",
+				weekday_names[tm->tm_wday],
+				month_names[tm->tm_mon],
+				tm->tm_mday,
+				tm->tm_hour, tm->tm_min, tm->tm_sec,
+				tm->tm_year + 1900, tz);
 	return timebuf;
 }