icmptype is a comma-separated list in the config. When attempting to save, the array in $_POST['icmptype'] needs to be put into this format in $pconfig in case there are input errors and the user-entered data need to be re-displayed for correction. (cherry picked from commit 23057964d81019e8ed3adc944c77ca8a1a9c178f)
Related issues
Bug #7059: firewall_rules_edit.php - strlen error when there are input errors
Fix #7059 Set expected icmptypes format
icmptype is a comma-separated list in the config. When attempting to save, the array in $_POST['icmptype'] needs to be put into this format in $pconfig in case there are input errors and the user-entered data need to be re-displayed for correction.
(cherry picked from commit 23057964d81019e8ed3adc944c77ca8a1a9c178f)