[PATCH 07/10] revert: Catch incompatible command-line options early

[Ramkumar Ramachandra <artagnon@gmail.com>]

Earlier, incompatible command-line options used to be caught in
pick_commits after parse_args has parsed the options and populated the
options structure; a lot of unncessary work has already been done, and
significant amount of cleanup is required to die at this stage.
Instead, hand over this responsibility to parse_args so that the
program can die early.  Also write a die_opt_incompabile function to
handle incompatible options in a general manner; it will be used more
extensively as more command-line options are introduced later in the
series.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
---
 builtin/revert.c |   34 +++++++++++++++++++++++-----------
 1 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/builtin/revert.c b/builtin/revert.c
index 2e5f260..1c6c102 100644
--- a/builtin/revert.c
+++ b/builtin/revert.c
@@ -80,6 +80,22 @@ static int option_parse_x(const struct option *opt,
 	return 0;
 }
 
+static void verify_opt_compatible(const char *me, const char *base_opt, ...)
+{
+	const char *this_opt;
+	va_list ap;
+	int set;
+
+	va_start(ap, base_opt);
+	while ((this_opt = va_arg(ap, const char *))) {
+		set = va_arg(ap, int);
+		if (set)
+			die(_("%s: %s cannot be used with %s"),
+				me, this_opt, base_opt);
+	}
+	va_end(ap);
+}
+
 static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 {
 	const char * const * usage_str = revert_or_cherry_pick_usage(opts);
@@ -116,6 +132,13 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 	if (opts->commit_argc < 2)
 		usage_with_options(usage_str, options);
 
+	if (opts->allow_ff)
+		verify_opt_compatible(me, "--ff",
+				"--signoff", opts->signoff,
+				"--no-commit", opts->no_commit,
+				"-x", opts->record_origin,
+				"--edit", opts->edit,
+				NULL);
 	opts->commit_argv = argv;
 }
 
@@ -556,17 +579,6 @@ static int pick_commits(struct replay_opts *opts)
 	struct commit *commit;
 
 	setenv(GIT_REFLOG_ACTION, me, 0);
-	if (opts->allow_ff) {
-		if (opts->signoff)
-			die(_("cherry-pick --ff cannot be used with --signoff"));
-		if (opts->no_commit)
-			die(_("cherry-pick --ff cannot be used with --no-commit"));
-		if (opts->record_origin)
-			die(_("cherry-pick --ff cannot be used with -x"));
-		if (opts->edit)
-			die(_("cherry-pick --ff cannot be used with --edit"));
-	}
-
 	read_and_refresh_cache(me, opts);
 
 	prepare_revs(&revs, opts);
-- 
1.7.5.GIT