When making an associated firewall rule for a port forward, do not craft what would be an invalid port range.
When saving a firewall rule, safely handle an empty ICMP subtype list
When generating firewall rules, only check src/dst ports for protocols that use ports, otherwise the ports don't make it into the rule anyway so the errors are meaningless.
Related issues
Regression #14267: PHP error when saving an ICMP firewall rule with no subtypes selected
Added by Jim Pingle over 2 years ago
Multiple issues with ICMP NAT/Rules. Fixes #14267
craft what would be an invalid port range.
that use ports, otherwise the ports don't make it into the rule anyway
so the errors are meaningless.