Support 'raw' date format

Talking about --date, one thing I wanted for the 1234567890 date was to
get things in the raw format. Sure, you get them with --pretty=raw, but it
felt a bit sad that you couldn't just ask for the date in raw format.

So here's a throw-away patch (meaning: I won't be re-sending it, because I
really don't think it's a big deal) to add "--date=raw". It just prints
out the internal raw git format - seconds since epoch plus timezone (put
another way: 'date +"%s %z"' format)
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/rev-list-options.txt

@@ -13,7 +13,7 @@ include::pretty-options.txt[]
 
 	Synonym for `--date=relative`.
 
---date={relative,local,default,iso,rfc,short}::
+--date={relative,local,default,iso,rfc,short,raw}::
 
 	Only takes effect for dates shown in human-readable format, such
 	as when using "--pretty". `log.date` config variable sets a default
@@ -31,6 +31,8 @@ format, often found in E-mail messages.
 +
 `--date=short` shows only date but not time, in `YYYY-MM-DD` format.
 +
+`--date=raw` shows the date in the internal raw git format `%s %z` format.
++
 `--date=default` shows timestamps in the original timezone
 (either committer's or author's).
 

cache.h

@@ -696,7 +696,8 @@ enum date_mode {
 	DATE_SHORT,
 	DATE_LOCAL,
 	DATE_ISO8601,
-	DATE_RFC2822
+	DATE_RFC2822,
+	DATE_RAW
 };
 
 const char *show_date(unsigned long time, int timezone, enum date_mode mode);

date.c

@@ -89,6 +89,11 @@ const char *show_date(unsigned long time, int tz, enum date_mode mode)
 	struct tm *tm;
 	static char timebuf[200];
 
+	if (mode == DATE_RAW) {
+		snprintf(timebuf, sizeof(timebuf), "%lu %+05d", time, tz);
+		return timebuf;
+	}
+
 	if (mode == DATE_RELATIVE) {
 		unsigned long diff;
 		struct timeval now;
@@ -615,6 +620,8 @@ enum date_mode parse_date_format(const char *format)
 		return DATE_LOCAL;
 	else if (!strcmp(format, "default"))
 		return DATE_NORMAL;
+	else if (!strcmp(format, "raw"))
+		return DATE_RAW;
 	else
 		die("unknown date format %s", format);
 }