daemon: use an argv_array to exec children

Our struct child_process already has its own argv_array.
Let's use that to avoid having to format options into
separate buffers.

Note that we'll need to declare the child process outside of
the run_service_command() helper to do this. But that opens
up a further simplification, which is that the helper can
append to our argument list, saving each caller from
specifying "." manually.

Signed-off-by: Jeff King <peff@peff.net>

daemon.c

@@ -449,46 +449,42 @@ static void copy_to_log(int fd)
 	fclose(fp);
 }
 
-static int run_service_command(const char **argv)
+static int run_service_command(struct child_process *cld)
 {
-	struct child_process cld = CHILD_PROCESS_INIT;
-
-	cld.argv = argv;
-	cld.git_cmd = 1;
-	cld.err = -1;
-	if (start_command(&cld))
+	argv_array_push(&cld->args, ".");
+	cld->git_cmd = 1;
+	cld->err = -1;
+	if (start_command(cld))
 		return -1;
 
 	close(0);
 	close(1);
 
-	copy_to_log(cld.err);
+	copy_to_log(cld->err);
 
-	return finish_command(&cld);
+	return finish_command(cld);
 }
 
 static int upload_pack(void)
 {
-	/* Timeout as string */
-	char timeout_buf[64];
-	const char *argv[] = { "upload-pack", "--strict", NULL, ".", NULL };
-
-	argv[2] = timeout_buf;
-
-	snprintf(timeout_buf, sizeof timeout_buf, "--timeout=%u", timeout);
-	return run_service_command(argv);
+	struct child_process cld = CHILD_PROCESS_INIT;
+	argv_array_pushl(&cld.args, "upload-pack", "--strict", NULL);
+	argv_array_pushf(&cld.args, "--timeout=%u", timeout);
+	return run_service_command(&cld);
 }
 
 static int upload_archive(void)
 {
-	static const char *argv[] = { "upload-archive", ".", NULL };
-	return run_service_command(argv);
+	struct child_process cld = CHILD_PROCESS_INIT;
+	argv_array_push(&cld.args, "upload-archive");
+	return run_service_command(&cld);
 }
 
 static int receive_pack(void)
 {
-	static const char *argv[] = { "receive-pack", ".", NULL };
-	return run_service_command(argv);
+	struct child_process cld = CHILD_PROCESS_INIT;
+	argv_array_push(&cld.args, "receive-pack");
+	return run_service_command(&cld);
 }
 
 static struct daemon_service daemon_service[] = {