#include <nghttp2/nghttp2.h>

void nghttp2_option_set_server_fallback_rfc7540_priorities(nghttp2_option *option, int val)

This option, if set to nonzero, allows server to fallback to RFC 7540 priorities if SETTINGS_NO_RFC7540_PRIORITIES was not received from client, and server submitted nghttp2_settings_id.NGHTTP2_SETTINGS_NO_RFC7540_PRIORITIES = 1 via nghttp2_submit_settings(). Most of the advanced functionality for RFC 7540 priorities are still disabled. This fallback only enables the minimal feature set of RFC 7540 priorities to deal with priority signaling from client.

Client session ignores this option.