cmd_bisect__helper: defer parsing no-checkout flag

cmd_bisect__helper() is intended as a temporary shim layer serving as an
interface for git-bisect.sh. This function and git-bisect.sh should
eventually be replaced by a C implementation, cmd_bisect(), serving as
an entrypoint for all "git bisect ..." shell commands: cmd_bisect() will
only parse the first token following "git bisect", and dispatch the
remaining args to the appropriate function ["bisect_start()",
"bisect_next()", etc.].

Thus, cmd_bisect__helper() should not be responsible for parsing flags
like --no-checkout. Instead, let the --no-checkout flag remain in the
argv array, so it may be evaluated alongside the other options already
parsed by bisect_start().

Signed-off-by: Aaron Lipman <alipman88@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

bisect.c

@@ -989,7 +989,7 @@ void read_bisect_terms(const char **read_bad, const char **read_good)
  * If no_checkout is non-zero, the bisection process does not
  * checkout the trial commit but instead simply updates BISECT_HEAD.
  */
-enum bisect_error bisect_next_all(struct repository *r, const char *prefix, int no_checkout)
+enum bisect_error bisect_next_all(struct repository *r, const char *prefix)
 {
 	struct rev_info revs;
 	struct commit_list *tried;
@@ -997,6 +997,7 @@ enum bisect_error bisect_next_all(struct repository *r, const char *prefix, int
 	enum bisect_error res = BISECT_OK;
 	struct object_id *bisect_rev;
 	char *steps_msg;
+	int no_checkout = ref_exists("BISECT_HEAD");
 	int first_parent_only = 0; /* TODO: pass --first-parent flag from git bisect start */
 
 	read_bisect_terms(&term_bad, &term_good);

bisect.h

@@ -58,9 +58,7 @@ enum bisect_error {
 	BISECT_INTERNAL_SUCCESS_MERGE_BASE = -11
 };
 
-enum bisect_error bisect_next_all(struct repository *r,
-		    const char *prefix,
-		    int no_checkout);
+enum bisect_error bisect_next_all(struct repository *r, const char *prefix);
 
 int estimate_bisect_steps(int all);
 

builtin/bisect--helper.c

@@ -19,7 +19,7 @@ static GIT_PATH_FUNC(git_path_head_name, "head-name")
 static GIT_PATH_FUNC(git_path_bisect_names, "BISECT_NAMES")
 
 static const char * const git_bisect_helper_usage[] = {
-	N_("git bisect--helper --next-all [--no-checkout]"),
+	N_("git bisect--helper --next-all"),
 	N_("git bisect--helper --write-terms <bad_term> <good_term>"),
 	N_("git bisect--helper --bisect-clean-state"),
 	N_("git bisect--helper --bisect-reset [<commit>]"),
@@ -421,9 +421,9 @@ finish:
 	return res;
 }
 
-static int bisect_start(struct bisect_terms *terms, int no_checkout,
-			const char **argv, int argc)
+static int bisect_start(struct bisect_terms *terms, const char **argv, int argc)
 {
+	int no_checkout = 0;
 	int i, has_double_dash = 0, must_write_terms = 0, bad_seen = 0;
 	int flags, pathspec_pos, res = 0;
 	struct string_list revs = STRING_LIST_INIT_DUP;
@@ -632,7 +632,7 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		BISECT_TERMS,
 		BISECT_START
 	} cmdmode = 0;
-	int no_checkout = 0, res = 0, nolog = 0;
+	int res = 0, nolog = 0;
 	struct option options[] = {
 		OPT_CMDMODE(0, "next-all", &cmdmode,
 			 N_("perform 'git bisect next'"), NEXT_ALL),
@@ -654,8 +654,6 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 			 N_("print out the bisect terms"), BISECT_TERMS),
 		OPT_CMDMODE(0, "bisect-start", &cmdmode,
 			 N_("start the bisect session"), BISECT_START),
-		OPT_BOOL(0, "no-checkout", &no_checkout,
-			 N_("update BISECT_HEAD instead of checking out the current commit")),
 		OPT_BOOL(0, "no-log", &nolog,
 			 N_("no log for BISECT_WRITE")),
 		OPT_END()
@@ -671,7 +669,7 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 
 	switch (cmdmode) {
 	case NEXT_ALL:
-		res = bisect_next_all(the_repository, prefix, no_checkout);
+		res = bisect_next_all(the_repository, prefix);
 		break;
 	case WRITE_TERMS:
 		if (argc != 2)
@@ -713,7 +711,7 @@ int cmd_bisect__helper(int argc, const char **argv, const char *prefix)
 		break;
 	case BISECT_START:
 		set_terms(&terms, "bad", "good");
-		res = bisect_start(&terms, no_checkout, argv, argc);
+		res = bisect_start(&terms, argv, argc);
 		break;
 	default:
 		return error("BUG: unknown subcommand '%d'", cmdmode);

git-bisect.sh

@@ -153,7 +153,7 @@ bisect_next() {
 	git bisect--helper --bisect-next-check $TERM_GOOD $TERM_BAD $TERM_GOOD|| exit
 
 	# Perform all bisection computation, display and checkout
-	git bisect--helper --next-all $(test -f "$GIT_DIR/BISECT_HEAD" && echo --no-checkout)
+	git bisect--helper --next-all
 	res=$?
 
 	# Check if we should exit because bisection is finished