run-command tests: use strvec_pushv(), not argv assignment

As in the preceding commit change this API user to use strvec_pushv()
instead of assigning to the "argv" member directly. This leaves us
without test coverage of how the "argv" assignment in this API works,
but we'll be removing it in a subsequent commit.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/helper/test-run-command.c

@@ -31,7 +31,7 @@ static int parallel_next(struct child_process *cp,
 	if (number_callbacks >= 4)
 		return 0;
 
-	strvec_pushv(&cp->args, d->argv);
+	strvec_pushv(&cp->args, d->args.v);
 	strbuf_addstr(err, "preloaded output of a child\n");
 	number_callbacks++;
 	return 1;
@@ -274,7 +274,7 @@ static int quote_stress_test(int argc, const char **argv)
 		if (i < skip)
 			continue;
 
-		cp.argv = args.v;
+		strvec_pushv(&cp.args, args.v);
 		strbuf_reset(&out);
 		if (pipe_command(&cp, NULL, 0, &out, 0, NULL, 0) < 0)
 			return error("Failed to spawn child process");
@@ -396,7 +396,7 @@ int cmd__run_command(int argc, const char **argv)
 	}
 	if (argc < 3)
 		return 1;
-	proc.argv = (const char **)argv + 2;
+	strvec_pushv(&proc.args, (const char **)argv + 2);
 
 	if (!strcmp(argv[1], "start-command-ENOENT")) {
 		if (start_command(&proc) < 0 && errno == ENOENT)
@@ -408,7 +408,8 @@ int cmd__run_command(int argc, const char **argv)
 		exit(run_command(&proc));
 
 	jobs = atoi(argv[2]);
-	proc.argv = (const char **)argv + 3;
+	strvec_clear(&proc.args);
+	strvec_pushv(&proc.args, (const char **)argv + 3);
 
 	if (!strcmp(argv[1], "run-command-parallel"))
 		exit(run_processes_parallel(jobs, parallel_next,