Roundcube 1.6 complete release - Throwing PHP Warnings in error.log

[neilpb]

Hi RC forum members  ,

We recently upgraded from RC 1.5.2 to 1.6.0, Everything seems to be running OK except for some PHP warnings being thrown into error.log file

PHP Warning:  Undefined array key 2 in /usr/share/roundcubemail/program/include/rcmail_attachment_handler.php on line 64
PHP Warning:  Undefined array key "" in /usr/share/roundcubemail/program/lib/Roundcube/rcube_imap.php on line 1045
PHP Warning:  Undefined array key "" in /usr/share/roundcubemail/program/lib/Roundcube/rcube_imap.php on line 1061
PHP Warning:  Undefined array key "search" in /usr/share/roundcubemail/program/actions/mail/check_recent.php on line 55
PHP Warning:  Undefined array key "search" in /usr/share/roundcubemail/program/actions/mail/check_recent.php on line 77
PHP Warning:  Undefined array key "ALL" in /usr/share/roundcubemail/program/lib/Roundcube/rcube_result_index.php on line 427
PHP Warning:  Undefined array key "_from" in /usr/share/roundcubemail/program/actions/mail/mark.php on line 114
PHP Warning:  Undefined array key "_from" in /usr/share/roundcubemail/program/actions/mail/mark.php on line 49
PHP Warning:  Undefined array key 0 in /usr/share/roundcubemail/program/lib/Roundcube/rcube_imap_generic.php on line 2577
PHP Warning:  Undefined array key 1 in /usr/share/roundcubemail/program/lib/Roundcube/rcube_imap_generic.php on line 2585

I have traced the particular lines for some of these an have implemented some extra logic check on array keys, though not sure if this makes things worse. Does any one know why this is happening?, I did not see these errors under 1.5.2. The last 6 in that list seem to be occurring the most. We are running RC 1.6.0 with Caddy 2.6.2 and PHP 8.0.26 inside a docker container.