Method write_request

external/httplib.h:7656–7772

}

inline bool ClientImpl::write_request(Stream &strm, Request &req,
                                      bool close_connection, Error &error) {
  // Prepare additional headers
  if (close_connection) {
    if (!req.has_header("Connection")) {
      req.set_header("Connection", "close");
    }
  }

  if (!req.has_header("Host")) {
    if (is_ssl()) {
      if (port_ == 443) {
        req.set_header("Host", host_);
      } else {
        req.set_header("Host", host_and_port_);
      }
    } else {
      if (port_ == 80) {
        req.set_header("Host", host_);
      } else {
        req.set_header("Host", host_and_port_);
      }
    }
  }

  if (!req.has_header("Accept")) { req.set_header("Accept", "*/*"); }

#ifndef CPPHTTPLIB_NO_DEFAULT_USER_AGENT
  if (!req.has_header("User-Agent")) {
    auto agent = std::string("cpp-httplib/") + CPPHTTPLIB_VERSION;
    req.set_header("User-Agent", agent);
  }
#endif

  if (req.body.empty()) {
    if (req.content_provider_) {
      if (!req.is_chunked_content_provider_) {
        if (!req.has_header("Content-Length")) {
          auto length = std::to_string(req.content_length_);
          req.set_header("Content-Length", length);
        }
      }
    } else {
      if (req.method == "POST" || req.method == "PUT" ||
          req.method == "PATCH") {
        req.set_header("Content-Length", "0");
      }
    }
  } else {
    if (!req.has_header("Content-Type")) {
      req.set_header("Content-Type", "text/plain");
    }

    if (!req.has_header("Content-Length")) {
      auto length = std::to_string(req.body.size());
      req.set_header("Content-Length", length);
    }
  }