When opening a new private message from a user with CAP draft/chathistory enabled causes it to request the private message history from the server which raises a failure message.

Gamja is latest built from master branch (rev 7138e437), IRC server is unrealircd 6.0.4

Raw Example:

< CAP stuff on connect >
CAP REQ :account-notify away-notify batch chghost echo-message extended-join invite-notify labeled-response message-tags multi-prefix sasl server-time setname draft/chathistory draft/extended-monitor
:irc.lan CAP terst ACK :account-notify away-notify batch chghost echo-message extended-join invite-notify labeled-response message-tags multi-prefix sasl server-time setname draft/chathistory draft/extended-monitor 
<MOTD, etc>
<Get message from adamus1red>
MONITOR + adamus1red
@label=2 WHO adamus1red %tfhnrua,0
@label=3 CHATHISTORY BEFORE adamus1red timestamp=2022-08-22T10:45:01.632Z 50
:irc.lan 730 terst :adamus1red!~M@this.is.my.vhost
@label=2 :irc.lan BATCH +QrRa85QmK7yw4QMO9cbOg5 labeled-response
@batch=QrRa85QmK7yw4QMO9cbOg5 :irc.lan 354 terst 0 ~M this.is.my.vhost adamus1red Hrs* adamus1red :Mario
@batch=QrRa85QmK7yw4QMO9cbOg5 :irc.lan 315 terst adamus1red :End of /WHO list.
:irc.lan BATCH -QrRa85QmK7yw4QMO9cbOg5
@label=3 :irc.lan FAIL CHATHISTORY INVALID_TARGET BEFORE adamus1red :Messages could not be retrieved, not an existing channel