cherry-pick: do not expect file arguments

If a commit-ish passed to cherry-pick or revert happens to have a file
of the same name, git complains that the argument is ambiguous and
advises to use '--'. To make things worse, the '--' argument is removed
by parse_options, und so passing '--' has no effect.

Instead, always interpret cherry-pick/revert arguments as revisions.

Signed-off-by: Clemens Buchacher <drizzd@aon.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/revert.c

@@ -181,12 +181,15 @@ static void parse_args(int argc, const char **argv, struct replay_opts *opts)
 	if (opts->subcommand != REPLAY_NONE) {
 		opts->revs = NULL;
 	} else {
+		struct setup_revision_opt s_r_opt;
 		opts->revs = xmalloc(sizeof(*opts->revs));
 		init_revisions(opts->revs, NULL);
 		opts->revs->no_walk = 1;
 		if (argc < 2)
 			usage_with_options(usage_str, options);
-		argc = setup_revisions(argc, argv, opts->revs, NULL);
+		memset(&s_r_opt, 0, sizeof(s_r_opt));
+		s_r_opt.assume_dashdash = 1;
+		argc = setup_revisions(argc, argv, opts->revs, &s_r_opt);
 	}
 
 	if (argc > 1)

revision.c

@@ -1715,17 +1715,21 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 		submodule = opt->submodule;
 
 	/* First, search for "--" */
-	seen_dashdash = 0;
-	for (i = 1; i < argc; i++) {
-		const char *arg = argv[i];
-		if (strcmp(arg, "--"))
-			continue;
-		argv[i] = NULL;
-		argc = i;
-		if (argv[i + 1])
-			append_prune_data(&prune_data, argv + i + 1);
+	if (opt && opt->assume_dashdash) {
 		seen_dashdash = 1;
-		break;
+	} else {
+		seen_dashdash = 0;
+		for (i = 1; i < argc; i++) {
+			const char *arg = argv[i];
+			if (strcmp(arg, "--"))
+				continue;
+			argv[i] = NULL;
+			argc = i;
+			if (argv[i + 1])
+				append_prune_data(&prune_data, argv + i + 1);
+			seen_dashdash = 1;
+			break;
+		}
 	}
 
 	/* Second, deal with arguments and options */

revision.h

@@ -183,6 +183,7 @@ struct setup_revision_opt {
 	const char *def;
 	void (*tweak)(struct rev_info *, struct setup_revision_opt *);
 	const char *submodule;
+	int assume_dashdash;
 };
 
 extern void init_revisions(struct rev_info *revs, const char *prefix);