[PATCH 1/3] Use parse_date_format() convenience function for converting a format string to an enum date_mode in revisions.c

[Andy Parkins <andyparkins@gmail.com>]

parse_date_format() is passed a string that is compared against a
pre-defined list and converted to an enum date_format.  The table is as
follows:

 - "relative"         => DATE_RELATIVE
 - "iso8601" or "iso" => DATE_ISO8601
 - "rfc2822"          => DATE_RFC2822
 - "short"            => DATE_SHORT
 - "local"            => DATE_LOCAL
 - "default"          => DATE_NORMAL

In the event that none of these strings is found, the function die()s.

Then we use parse_date_format() in revisions.c to parse the --date
parameter.  The --date parameter was previously handled in revisions.c
with a list of if(strcmp()) calls; now parse_date_format() is called
instead.

Signed-off-by: Andy Parkins <andyparkins@gmail.com>
---
 cache.h    |    1 +
 date.c     |   20 ++++++++++++++++++++
 revision.c |   17 +----------------
 3 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/cache.h b/cache.h
index 8246500..5587f7e 100644
--- a/cache.h
+++ b/cache.h
@@ -432,6 +432,7 @@ const char *show_date(unsigned long time, int timezone, enum date_mode mode);
 int parse_date(const char *date, char *buf, int bufsize);
 void datestamp(char *buf, int bufsize);
 unsigned long approxidate(const char *);
+enum date_mode parse_date_format(const char *format);
 
 extern const char *git_author_info(int);
 extern const char *git_committer_info(int);
diff --git a/date.c b/date.c
index 93bef6e..8f70500 100644
--- a/date.c
+++ b/date.c
@@ -584,6 +584,26 @@ int parse_date(const char *date, char *result, int maxlen)
 	return date_string(then, offset, result, maxlen);
 }
 
+enum date_mode parse_date_format(const char *format)
+{
+	if (!strcmp(format, "relative"))
+		return DATE_RELATIVE;
+	else if (!strcmp(format, "iso8601") ||
+		 !strcmp(format, "iso"))
+		return DATE_ISO8601;
+	else if (!strcmp(format, "rfc2822") ||
+		 !strcmp(format, "rfc"))
+		return DATE_RFC2822;
+	else if (!strcmp(format, "short"))
+		return DATE_SHORT;
+	else if (!strcmp(format, "local"))
+		return DATE_LOCAL;
+	else if (!strcmp(format, "default"))
+		return DATE_NORMAL;
+	else
+		die("unknown date format %s", format);
+}
+
 void datestamp(char *buf, int bufsize)
 {
 	time_t now;
diff --git a/revision.c b/revision.c
index 33d092c..75cd0c6 100644
--- a/revision.c
+++ b/revision.c
@@ -1134,22 +1134,7 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, const ch
 				continue;
 			}
 			if (!strncmp(arg, "--date=", 7)) {
-				if (!strcmp(arg + 7, "relative"))
-					revs->date_mode = DATE_RELATIVE;
-				else if (!strcmp(arg + 7, "iso8601") ||
-					 !strcmp(arg + 7, "iso"))
-					revs->date_mode = DATE_ISO8601;
-				else if (!strcmp(arg + 7, "rfc2822") ||
-					 !strcmp(arg + 7, "rfc"))
-					revs->date_mode = DATE_RFC2822;
-				else if (!strcmp(arg + 7, "short"))
-					revs->date_mode = DATE_SHORT;
-				else if (!strcmp(arg + 7, "local"))
-					revs->date_mode = DATE_LOCAL;
-				else if (!strcmp(arg + 7, "default"))
-					revs->date_mode = DATE_NORMAL;
-				else
-					die("unknown date format %s", arg);
+				revs->date_mode = parse_date_format(arg + 7);
 				continue;
 			}
 			if (!strcmp(arg, "--log-size")) {
-- 
1.5.3.rc5.11.g312e