Comment 26 for bug 1821343

Verified according to test case in description for xenial:

root@xenial:~# dpkg -l | grep slapd
ii slapd 2.4.42+dfsg-2ubuntu3.5 amd64 OpenLDAP server (slapd)

root@xenial:~# systemctl status slapd
● slapd.service - LSB: OpenLDAP standalone server (Lightweight Directory Access Protocol)
   Loaded: loaded (/etc/init.d/slapd; bad; vendor preset: enabled)
  Drop-In: /lib/systemd/system/slapd.service.d
           └─slapd-remain-after-exit.conf
   Active: active (running) since Mon 2019-04-22 20:23:10 UTC; 14s ago
     Docs: man:systemd-sysv-generator(8)
   CGroup: /system.slice/slapd.service
           └─5920 /usr/sbin/slapd -h ldap:/// ldapi:/// -g openldap -u openldap -F /etc/ldap/slapd.d

root@xenial:~# kill -9 5920

root@xenial:~# systemctl status slapd
● slapd.service - LSB: OpenLDAP standalone server (Lightweight Directory Access Protocol)
   Loaded: loaded (/etc/init.d/slapd; bad; vendor preset: enabled)
  Drop-In: /lib/systemd/system/slapd.service.d
           └─slapd-remain-after-exit.conf
   Active: inactive (dead) since Mon 2019-04-22 20:23:30 UTC; 1s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 5989 ExecStop=/etc/init.d/slapd stop (code=exited, status=0/SUCCESS)

root@xenial:~# systemctl cat slapd
# /run/systemd/generator.late/slapd.service
# Automatically generated by systemd-sysv-generator

[Unit]
Documentation=man:systemd-sysv-generator(8)
SourcePath=/etc/init.d/slapd
Description=LSB: OpenLDAP standalone server (Lightweight Directory Access Protocol)
Before=multi-user.target
Before=multi-user.target
Before=multi-user.target
Before=graphical.target
Before=shutdown.target
After=remote-fs.target
After=network-online.target
After=systemd-journald-dev-log.socket
Wants=network-online.target
Conflicts=shutdown.target

[Service]
Type=forking
Restart=no
TimeoutSec=5min
IgnoreSIGPIPE=no
KillMode=process
GuessMainPID=no
RemainAfterExit=yes
ExecStart=/etc/init.d/slapd start
ExecStop=/etc/init.d/slapd stop

# /lib/systemd/system/slapd.service.d/slapd-remain-after-exit.conf
[Service]
Type=forking
RemainAfterExit=no