DHCPv6 and DHCP options on the same line in `dhcpcd.conf(5)` can cause problems

[zacknewman]

dhcpcd.conf(5) states:

⋮
     option option
             Requests the option from the server.  It can be a variable to be
             used in dhcpcd-run-hooks(8) or the numerical value.  You can
             specify more options separated by commas, spaces or more option
             lines.  Prepend dhcp6_ to option to request a DHCPv6 option.  If
             no DHCPv6 options are configured, then DHCPv4 options are mapped
             to equivalent DHCPv6 options.

             Prepend nd_ to option to handle ND options, but this only works
             for the nooption, reject and require options.

             To see a list of options you can use, call dhcpcd with the -V,
             --variables argument.
⋮

It explicitly states that DHCPv6, ND, and DHCP options are allowed on the same line; thus I believe there is a bug. For example, the following config parses just fine:

noipv6rs
denyinterfaces !(ixl2)
allowinterfaces ixl2
script ""
link_rcvbuf 65536
interface ixl2
	duid
	fqdn disable
	iaid 0
	ia_na 0
	ia_pd 0/::/60 -
	ipv6rs
	# DHCPv6 options to remove. Copy-pasted from `dhcpcd -V` with `dhcp6_` prepended per `dhcpcd.conf(5)`.
	nooption dhcp6_name_servers,dhcp6_domain_search,dhcp6_sntp_servers,dhcp6_fqdn,dhcp6_posix_timezone,dhcp6_tzdb_timezone,dhcp6_ntp_server
	# ND options to remove. Copy-pasted from `dhcpcd -V` with `nd_` prepended per `dhcpcd.conf(5)`.
	nooption nd_mtu,nd_rdnss,nd_dnssl
	# DHCP options to remove. Copy-pasted from `dhcpcd -V`.
	nooption time_offset,time_servers,ien116_name_servers,domain_name_servers,host_name,domain_name,interface_mtu,ntp_servers,fqdn,posix_timezone,tzdb_timezone,name_service_search,domain_search
	# DHCPv6 options to request. Copy-pasted from `dhcpcd -V` with `dhcp6_` prepended per `dhcpcd.conf(5)`.
	option dhcp6_rapid_commit
	# DHCP options to request. Copy-pasted from `dhcpcd -V`.
	option rapid_commit
	persistent
	# DHCPv6 options to require. Copy-pasted from `dhcpcd -V` with `dhcp6_` prepended per `dhcpcd.conf(5)`.
	require dhcp6_server_id
	# DHCP options to require. Copy-pasted from `dhcpcd -V`.
	require dhcp_message_type,dhcp_server_identifier
	waitip 64

On the other hand, if you merge the two require lines (i.e., require dhcp6_server_id,dhcp_message_type,dhcp_server_identifier), dhcpcd(8) logs an "unknown option" error:

May 10 10:28:56 router dhcpcd[44420]: unknown option: dhcp6_server_id,dhcp_message_type,dhcp_server_identifier

Similarly, if you merge the three nooption lines:

⋮
	nooption dhcp6_name_servers,dhcp6_domain_search,dhcp6_sntp_servers,dhcp6_fqdn,dhcp6_posix_timezone,dhcp6_tzdb_timezone,dhcp6_ntp_server,nd_mtu,nd_rdnss,nd_dnssl,time_offset,time_servers,ien116_name_servers,domain_name_servers,host_name,domain_name,interface_mtu,ntp_servers,fqdn,posix_timezone,tzdb_timezone,name_service_search,domain_search
⋮

dhcpcd(8) logs an "unknown option" error:

May 10 10:28:56 router dhcpcd[44420]: unknown option: dhcp6_name_servers,dhcp6_domain_search,dhcp6_sntp_servers,dhcp6_fqdn,dhcp6_posix_timezone,dhcp6_tzdb_timezone,dhcp6_ntp_server,nd_mtu,nd_rdnss,nd_dnssl,time_offset,time_servers,ien116_name_servers,domain_name_servers,host_name,domain_name,interface_mtu,ntp_servers,fqdn,posix_timezone,tzdb_timezone,name_service_search,domain_search