Function append_json_object_or_empty

ds4_server.c:2225–2240

            goto bad;
        }
        chat_msg_add_tool_call_id(msg, id);
        buf b = {0};
        buf_puts(&b, msg->content ? msg->content : "");
        const size_t begin = b.len;
        buf_puts(&b, "<tool_result>");
        append_tool_result_text(&b, nested.content);
        buf_puts(&b, "</tool_result>");
        /* Preserve parsed boundaries, not just markup which ordinary user
         * text can also contain. V4.1 orders and separates these blocks. */
        msg->tool_results = xrealloc(msg->tool_results,
            (size_t)(msg->tool_results_len + 1) * sizeof(msg->tool_results[0]));
        msg->tool_results[msg->tool_results_len++] = (tool_result_span){
            .begin = begin, .end = b.len, .id = id ? xstrdup(id) : NULL,
            .content = nested.content};
        nested.content = NULL;
        free(msg->content);
        msg->content = buf_take(&b);
        if (nested.images.len) {
            size_t total = msg->images.len + nested.images.len;