Description of problem:

When creating a configuration with multiple prefix lists, without specifying the seq number and we load the file with the frr-reload.py script, the prefix lists are duplicated. We don't have a case but this was noted by a user.

Version-Release number of selected component (if applicable):

frr-7.5-4.el8_4.2.x86_64

How reproducible:

Always

Steps to Reproduce:
1. Start with an empty frr.conf, then load

og file /etc/frr/frr.log informational
log timestamp precision 3
hostname kind-worker2
ip nht resolve-via-default
ipv6 nht resolve-via-default
route-map 172.18.0.5-in deny 20

ip prefix-list 172.18.0.5-pl-ipv4 permit 192.168.10.1/32

ip prefix-list 172.18.0.5-pl-ipv4 permit 192.168.10.3/32

ip prefix-list 172.18.0.5-pl-ipv4 permit 192.168.10.0/32

ip prefix-list 172.18.0.5-pl-ipv4 permit 192.168.10.2/32

ip prefix-list 172.18.0.5-pl-ipv4 deny any
ipv6 prefix-list 172.18.0.5-pl-ipv4 deny any

route-map 172.18.0.5-out permit 7
match ip address prefix-list 172.18.0.5-pl-ipv4
route-map 172.18.0.5-out permit 8
match ipv6 address prefix-list 172.18.0.5-pl-ipv4
route-map 172.18.0.6-in deny 20

ip prefix-list 172.18.0.6-pl-ipv4 permit 192.168.10.1/32

ip prefix-list 172.18.0.6-pl-ipv4 permit 192.168.10.3/32

ip prefix-list 172.18.0.6-pl-ipv4 permit 192.168.10.0/32

ip prefix-list 172.18.0.6-pl-ipv4 permit 192.168.10.2/32

ip prefix-list 172.18.0.6-pl-ipv4 deny any
ipv6 prefix-list 172.18.0.6-pl-ipv4 deny any

route-map 172.18.0.6-out permit 7
match ip address prefix-list 172.18.0.6-pl-ipv4
route-map 172.18.0.6-out permit 8
match ipv6 address prefix-list 172.18.0.6-pl-ipv4

router bgp 64512
no bgp ebgp-requires-policy
no bgp network import-check
no bgp default ipv4-unicast

neighbor 172.18.0.5 remote-as 64512
neighbor 172.18.0.5 port 179
neighbor 172.18.0.5 timers 30 90

neighbor 172.18.0.6 remote-as 64512
neighbor 172.18.0.6 port 179
neighbor 172.18.0.6 timers 30 90

address-family ipv4 unicast
neighbor 172.18.0.5 activate
neighbor 172.18.0.5 route-map 172.18.0.5-in in
neighbor 172.18.0.5 route-map 172.18.0.5-out out
exit-address-family
address-family ipv6 unicast
neighbor 172.18.0.5 activate
neighbor 172.18.0.5 route-map 172.18.0.5-in in
neighbor 172.18.0.5 route-map 172.18.0.5-out out
exit-address-family

address-family ipv4 unicast
neighbor 172.18.0.6 activate
neighbor 172.18.0.6 route-map 172.18.0.6-in in
neighbor 172.18.0.6 route-map 172.18.0.6-out out
exit-address-family
address-family ipv6 unicast
neighbor 172.18.0.6 activate
neighbor 172.18.0.6 route-map 172.18.0.6-in in
neighbor 172.18.0.6 route-map 172.18.0.6-out out
exit-address-family
address-family ipv4 unicast
network 192.168.10.0/32
network 192.168.10.1/32
network 192.168.10.2/32
network 192.168.10.3/32
exit-address-family

2.
3.

Actual results:
3 occurrences of each prefix list, when running vtysh show running-conf

ip prefix-list 172.18.0.5-pl-ipv4 seq 5 permit 192.168.10.1/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 10 permit 192.168.10.3/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 15 permit 192.168.10.0/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 20 permit 192.168.10.2/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 25 deny any
ip prefix-list 172.18.0.5-pl-ipv4 seq 30 permit 192.168.10.1/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 35 permit 192.168.10.3/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 40 permit 192.168.10.0/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 45 permit 192.168.10.2/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 50 deny any
ip prefix-list 172.18.0.5-pl-ipv4 seq 55 permit 192.168.10.1/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 60 permit 192.168.10.3/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 65 permit 192.168.10.0/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 70 permit 192.168.10.2/32
ip prefix-list 172.18.0.5-pl-ipv4 seq 75 deny any

Expected results:

Only one occurrency per entry

Additional info: