sequencer: use static initializers for replay_opts

This change is not completely faithful: instead of initializing all fields
to 0, we choose to initialize command and subcommand to -1 (instead of
defaulting to REPLAY_REVERT and REPLAY_NONE, respectively). Practically,
it makes no difference at all, but future-proofs the code to require
explicit assignments for both fields.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/revert.c

@@ -178,10 +178,9 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 
 int cmd_revert(int argc, const char **argv, const char *prefix)
 {
-	struct replay_opts opts;
+	struct replay_opts opts = REPLAY_OPTS_INIT;
 	int res;
 
-	memset(&opts, 0, sizeof(opts));
 	if (isatty(0))
 		opts.edit = 1;
 	opts.action = REPLAY_REVERT;
@@ -195,10 +194,9 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
 
 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 {
-	struct replay_opts opts;
+	struct replay_opts opts = REPLAY_OPTS_INIT;
 	int res;
 
-	memset(&opts, 0, sizeof(opts));
 	opts.action = REPLAY_PICK;
 	git_config(git_default_config, NULL);
 	parse_args(argc, argv, &opts);

sequencer.h

@@ -47,6 +47,7 @@ struct replay_opts {
 	/* Only used by REPLAY_NONE */
 	struct rev_info *revs;
 };
+#define REPLAY_OPTS_INIT { -1, -1 }
 
 int sequencer_pick_revisions(struct replay_opts *opts);