core, job: fix breakage of ordering dependencies by systemctl reload command

core, job: fix breakage of ordering dependencies by systemctl reload command

Currently, systemctl reload command breaks ordering dependencies if it's
executed when its target service unit is in activating state.

For example, prepare A.service, B.service and C.target as follows:

    # systemctl cat A.service B.service C.target
    # /etc/systemd/system/A.service
    [Unit]
    Description=A

    [Service]
    Type=oneshot
    ExecStart=/usr/bin/echo A1
    ExecStart=/usr/bin/sleep 60
    ExecStart=/usr/bin/echo A2
    ExecReload=/usr/bin/echo A reloaded
    RemainAfterExit=yes

    # /etc/systemd/system/B.service
    [Unit]
    Description=B
    After=A.service

    [Service]
    Type=oneshot
    ExecStart=/usr/bin/echo B
    RemainAfterExit=yes

    # /etc/systemd/system/C.target
    [Unit]
    Description=C
    Wants=A.service B.service

Start them.

    # systemctl daemon-reload
    # systemctl start C.target

Then, we have:

    # LANG=C journalctl --no-pager -u A.service -u B.service -u C.target -b
    -- Logs begin at Mon 2019-09-09 00:25:06 EDT, end at Thu 2019-10-24 22:28:47 EDT. --
    Oct 24 22:27:47 localhost.localdomain systemd[1]: Starting A...
    Oct 24 22:27:47 localhost.localdomain systemd[1]: A.service: Child 967 belongs to A.service.
    Oct 24 22:27:47 localhost.localdomain systemd[1]: A.service: Main process exited, code=exited, status=0/SUCCESS
    Oct 24 22:27:47 localhost.localdomain systemd[1]: A.service: Running next main command for state start.
    Oct 24 22:27:47 localhost.localdomain systemd[1]: A.service: Passing 0 fds to service
    Oct 24 22:27:47 localhost.localdomain systemd[1]: A.service: About to execute: /usr/bin/sleep 60
    Oct 24 22:27:47 localhost.localdomain systemd[1]: A.service: Forked /usr/bin/sleep as 968
    Oct 24 22:27:47 localhost.localdomain systemd[968]: A.service: Executing: /usr/bin/sleep 60
    Oct 24 22:27:52 localhost.localdomain systemd[1]: A.service: Trying to enqueue job A.service/reload/replace
    Oct 24 22:27:52 localhost.localdomain systemd[1]: A.service: Merged into running job, re-running: A.service/reload as 1288
    Oct 24 22:27:52 localhost.localdomain systemd[1]: A.service: Enqueued job A.service/reload as 1288
    Oct 24 22:27:52 localhost.localdomain systemd[1]: A.service: Unit cannot be reloaded because it is inactive.
    Oct 24 22:27:52 localhost.localdomain systemd[1]: A.service: Job 1288 A.service/reload finished, result=invalid
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Passing 0 fds to service
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: About to execute: /usr/bin/echo B
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Forked /usr/bin/echo as 970
    Oct 24 22:27:52 localhost.localdomain systemd[970]: B.service: Executing: /usr/bin/echo B
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Failed to send unit change signal for B.service: Connection reset by peer
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Changed dead -> start
    Oct 24 22:27:52 localhost.localdomain systemd[1]: Starting B...
    Oct 24 22:27:52 localhost.localdomain echo[970]: B
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Child 970 belongs to B.service.
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Main process exited, code=exited, status=0/SUCCESS
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Changed start -> exited
    Oct 24 22:27:52 localhost.localdomain systemd[1]: B.service: Job 1371 B.service/start finished, result=done
    Oct 24 22:27:52 localhost.localdomain systemd[1]: Started B.
    Oct 24 22:27:52 localhost.localdomain systemd[1]: C.target: Job 1287 C.target/start finished, result=done
    Oct 24 22:27:52 localhost.localdomain systemd[1]: Reached target C.
    Oct 24 22:27:52 localhost.localdomain systemd[1]: C.target: Failed to send unit change signal for C.target: Connection reset by peer
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Child 968 belongs to A.service.
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Main process exited, code=exited, status=0/SUCCESS
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Running next main command for state start.
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Passing 0 fds to service
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: About to execute: /usr/bin/echo A2
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Forked /usr/bin/echo as 972
    Oct 24 22:28:47 localhost.localdomain systemd[972]: A.service: Executing: /usr/bin/echo A2
    Oct 24 22:28:47 localhost.localdomain echo[972]: A2
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Child 972 belongs to A.service.
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Main process exited, code=exited, status=0/SUCCESS
    Oct 24 22:28:47 localhost.localdomain systemd[1]: A.service: Changed start -> exited

The issue occurs not only in reload command, i.e.:

  - reload
  - try-restart
  - reload-or-restart
  - reload-or-try-restart commands

The cause of this issue is that job_type_collapse() doesn't take care of the
activating state.

Fixes: #10464
(cherry picked from commit d1559793df555212271e490a4a72f55826caf5b4)

Resolves: #1766417