man: Document --job-mode=triggering switch

man/systemctl.xml

@@ -1601,8 +1601,9 @@ Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output err
         <literal>replace-irreversibly</literal>,
         <literal>isolate</literal>,
         <literal>ignore-dependencies</literal>,
-        <literal>ignore-requirements</literal> or
-        <literal>flush</literal>. Defaults to
+        <literal>ignore-requirements</literal>,
+        <literal>flush</literal>, or
+        <literal>triggering</literal>. Defaults to
         <literal>replace</literal>, except when the
         <command>isolate</command> command is used which implies the
         <literal>isolate</literal> job mode.</para>
@@ -1647,6 +1648,13 @@ Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output err
         dependencies will still be honored.</para>
         </listitem>
 
+        <para><literal>triggering</literal> may only be used with
+        <command>systemctl stop</command>. In this mode, the specified
+        unit and any active units that trigger it are stopped. See the
+        discussion of
+        <varname>Triggers=</varname> in <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+        for more information about triggering units.</para>
+
       </varlistentry>
 
       <varlistentry>

src/core/transaction.c

@@ -1148,6 +1148,7 @@ int transaction_add_triggering_jobs(Transaction *tr, Unit *u) {
         int r;
 
         assert(tr);
+        assert(u);
 
         HASHMAP_FOREACH_KEY(v, trigger, u->dependencies[UNIT_TRIGGERED_BY], i) {
                 /* No need to stop inactive jobs */