reset.c: extract function for updating {ORIG_,}HEAD

By extracting the code for updating the HEAD and ORIG_HEAD symbolic
references to a separate function, we declutter cmd_reset() a bit and
we make it clear that e.g. the four variables {,sha1_}{,old_}orig are
only used by this code.

Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/reset.c

@@ -240,16 +240,35 @@ static const char **parse_args(const char **argv, const char *prefix, const char
 	return argv[0] ? get_pathspec(prefix, argv) : NULL;
 }
 
+static int update_refs(const char *rev, const unsigned char *sha1)
+{
+	int update_ref_status;
+	struct strbuf msg = STRBUF_INIT;
+	unsigned char *orig = NULL, sha1_orig[20],
+		*old_orig = NULL, sha1_old_orig[20];
+
+	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
+		old_orig = sha1_old_orig;
+	if (!get_sha1("HEAD", sha1_orig)) {
+		orig = sha1_orig;
+		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
+		update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
+	} else if (old_orig)
+		delete_ref("ORIG_HEAD", old_orig, 0);
+	set_reflog_message(&msg, "updating HEAD", rev);
+	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
+	strbuf_release(&msg);
+	return update_ref_status;
+}
+
 int cmd_reset(int argc, const char **argv, const char *prefix)
 {
 	int reset_type = NONE, update_ref_status = 0, quiet = 0;
 	int patch_mode = 0;
 	const char *rev;
-	unsigned char sha1[20], *orig = NULL, sha1_orig[20],
-				*old_orig = NULL, sha1_old_orig[20];
+	unsigned char sha1[20];
 	const char **pathspec = NULL;
 	struct commit *commit;
-	struct strbuf msg = STRBUF_INIT;
 	const struct option options[] = {
 		OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 		OPT_SET_INT(0, "mixed", &reset_type,
@@ -333,17 +352,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 
 	/* Any resets update HEAD to the head being switched to,
 	 * saving the previous head in ORIG_HEAD before. */
-	if (!get_sha1("ORIG_HEAD", sha1_old_orig))
-		old_orig = sha1_old_orig;
-	if (!get_sha1("HEAD", sha1_orig)) {
-		orig = sha1_orig;
-		set_reflog_message(&msg, "updating ORIG_HEAD", NULL);
-		update_ref(msg.buf, "ORIG_HEAD", orig, old_orig, 0, MSG_ON_ERR);
-	}
-	else if (old_orig)
-		delete_ref("ORIG_HEAD", old_orig, 0);
-	set_reflog_message(&msg, "updating HEAD", rev);
-	update_ref_status = update_ref(msg.buf, "HEAD", sha1, orig, 0, MSG_ON_ERR);
+	update_ref_status = update_refs(rev, sha1);
 
 	switch (reset_type) {
 	case HARD:
@@ -360,7 +369,5 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 
 	remove_branch_state();
 
-	strbuf_release(&msg);
-
 	return update_ref_status;
 }