MT#61856 control_ng: for JSON err resp, use own parser

There is a dedicated JSON parser, so use this.

Also leave some TODO'ers to think about adding own
`parser_arg` for JSON-like formatted data.

Change-Id: I5399ffb6ec74e88887b52fd63b96a8e44428c495

daemon/control_ng.c

@@ -697,6 +697,8 @@ static void prepare_resp_ctx(ng_command_ctx_t *command_ctx, const ng_parser_t *p
 	/* init as dict by default, if requested */
 	if (native)
 		parser->init(&command_ctx->parser_ctx, &command_ctx->ngbuf->buffer);
+	/* TODO: JSON-like structured data probably needs to have own `parser_arg`
+	 * because otherwise resp is always added as dictionary */
 	command_ctx->resp = parser->dict(&command_ctx->parser_ctx);
 	assert(command_ctx->resp.gen != NULL);
 }
@@ -740,13 +742,13 @@ static void control_ng_process_payload(ng_ctx *hctx, str *reply, str *data, cons
 		command_ctx.ngbuf->json = json_parser_new();
 		errstr = "Failed to parse JSON document";
 		if (!json_parser_load_from_data(command_ctx.ngbuf->json, data->s, data->len, NULL)) {
-			prepare_resp_ctx(&command_ctx, parser, false);
+			prepare_resp_ctx(&command_ctx, json_parser, false);
 			goto err_send;
 		}
 		command_ctx.req.json = json_parser_get_root(command_ctx.ngbuf->json);
 		errstr = "Could not decode JSON dictionary";
 		if (!command_ctx.req.json || !json_parser->is_dict(command_ctx.req)) {
-			prepare_resp_ctx(&command_ctx, parser, false);
+			prepare_resp_ctx(&command_ctx, json_parser, false);
 			goto err_send;
 		}
 	}
@@ -759,6 +761,8 @@ static void control_ng_process_payload(ng_ctx *hctx, str *reply, str *data, cons
 
 	parser = command_ctx.parser_ctx.parser;
 
+	/* TODO: JSON-like structured data probably needs to have own `parser_arg`
+	 * because otherwise resp is always added as dictionary */
 	command_ctx.resp = parser->dict(&command_ctx.parser_ctx);
 	assert(command_ctx.resp.gen != NULL);