[SR-Users] t_relay_cancel usage

in tm readme there is this kind of example regarding use of t_relay_cancel: if (method == CANCEL) { if (!t_relay_cancel()) { # implicit drop if relaying was successful, # nothing to do # corresponding INVITE transaction found but error occurred sl_reply("500", "Internal Server Error"); drop; } # bad luck, corresponding INVITE transaction is missing, # do the same as for INVITEs } if proxy is processing all invites statefully, why anything needs to be done when invite transaction corresponding the to cancel is missing? isn't it a case of unmatched cancel and the cancel could just be dropped? -- juha