Description of problem:

From the man page:
       ExecStart=
...
           This option may not
           be specified more than once, except when Type=oneshot is used in
           which case more than one ExecStart= line is accepted which are then
           invoked one by one, sequentially in the order they appear in the
           unit file.

However, in testing:
[root@nostromo ~]# cd /run/systemd/system
[root@nostromo system]# cat getty@.service
.include /lib/systemd/system/getty@.service

[Service]
ExecStart=-/sbin/agetty -f /run/test-issue --noclear %I 38400 linux
[root@nostromo system]# systemctl daemon-reload
[root@nostromo system]# systemctl show getty | grep ExecStart
ExecStart={ path=/sbin/agetty ; argv[]=/sbin/agetty --noclear %I 38400 linux ; ignore_errors=yes ; start_time=[n/a] ; stop_time=[n/a] ; pid=0 ; code=(null) ; status=0/0 }
ExecStart={ path=/sbin/agetty ; argv[]=/sbin/agetty -f /run/test-issue --noclear %I 38400 linux ; ignore_errors=yes ; start_time=[n/a] ; stop_time=[n/a] ; pid=0 ; code=(null) ; status=0/0 }

Either the docs are wrong, or the implementation is buggy. (getty@ is of Type idle, not oneshot.)

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

systemd-195-10.fc18.x86_64

How reproducible:

100%

Steps to Reproduce:
1. see above
  
Actual results:

ExecStart is extended with a second command

Expected results:

ExecStart is overridden

Additional info:

Copying the unit file wholesale and making the change works as expected.