service: don't take a command named like an option for one

A run/task/service whose command starts like an option without a ':'
lost its command, e.g. the example in finit.conf(5):

    run [2345] @joe:users logger "Hello world"

was registered as the log option, running "Hello world".  Same for
pidof, pidproxy, cgroupfs-mount, and in block format too.

The option parser matches with MATCH_CMD(), a prefix match, also for
the options with no trailing ':' to end the prefix: log, pid, cgroup,
respawn, nowarn, and the rest.

Match these against the whole token, allowing only the separator that
starts a value: "log:", "pid:", "cgroup." and "cgroup:".

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/conf-command.sh

@@ -89,6 +89,16 @@ retry 'assert_cmd pick "serv -np -i pick -- extra"'
 assert_desc "Dashes" pick
 assert_num_children 1 serv
 
+# Options are matched as whole tokens, so a command that merely starts
+# like one, pidof vs. pid, is still the command.
+say 'A command named like an option is the command'
+run "echo 'task lookalike {'             >  $FINIT_CONF"
+run "echo '    command = \"pidof serv\"' >> $FINIT_CONF"
+run "echo '}'                            >> $FINIT_CONF"
+run "initctl reload"
+
+retry 'assert_cmd lookalike "pidof serv"'
+
 # A tty block takes the same list, its command is the getty to run.
 # Asserting it is loaded is enough here, a getty in the test namespace
 # has no terminal to attach to.