1 files changed, 15 insertions, 8 deletions

diff --git a/src/core/unit.c b/src/core/unit.c
index cb79c7c6b1..4ace6b075b 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -193,7 +193,7 @@ int unit_add_name(Unit *u, const char *text) {
         if (r < 0)
                 return r;
 
-        if (i && unit_vtable[t]->no_instances)
+        if (i && !unit_type_may_template(t))
                 return -EINVAL;
 
         /* Ensure that this unit is either instanced or not instanced,
@@ -202,7 +202,7 @@ int unit_add_name(Unit *u, const char *text) {
         if (u->type != _UNIT_TYPE_INVALID && !u->instance != !i)
                 return -EINVAL;
 
-        if (unit_vtable[t]->no_alias && !set_isempty(u->names))
+        if (!unit_type_may_alias(t) && !set_isempty(u->names))
                 return -EEXIST;
 
         if (hashmap_size(u->manager->units) >= MANAGER_MAX_NAMES)
@@ -720,6 +720,9 @@ int unit_merge(Unit *u, Unit *other) {
         if (!u->instance != !other->instance)
                 return -EINVAL;
 
+        if (!unit_type_may_alias(u->type)) /* Merging only applies to unit names that support aliases */
+                return -EEXIST;
+
         if (other->load_state != UNIT_STUB &&
             other->load_state != UNIT_NOT_FOUND)
                 return -EEXIST;
@@ -776,9 +779,9 @@ int unit_merge(Unit *u, Unit *other) {
 }
 
 int unit_merge_by_name(Unit *u, const char *name) {
+        _cleanup_free_ char *s = NULL;
         Unit *other;
         int r;
-        _cleanup_free_ char *s = NULL;
 
         assert(u);
         assert(name);
@@ -1497,11 +1500,6 @@ int unit_start(Unit *u) {
         if (UNIT_IS_ACTIVE_OR_RELOADING(state))
                 return -EALREADY;
 
-        /* Make sure we don't enter a busy loop of some kind. */
-        r = unit_start_limit_test(u);
-        if (r < 0)
-                return r;
-
         /* Units that aren't loaded cannot be started */
         if (u->load_state != UNIT_LOADED)
                 return -EINVAL;
@@ -1543,6 +1541,11 @@ int unit_start(Unit *u) {
         if (!UNIT_VTABLE(u)->start)
                 return -EBADR;
 
+        /* Make sure we don't enter a busy loop of some kind. */
+        r = unit_start_limit_test(u);
+        if (r < 0)
+                return r;
+
         /* We don't suppress calls to ->start() here when we are
          * already starting, to allow this request to be used as a
          * "hurry up" call, for example when the unit is in some "auto
@@ -3222,6 +3225,10 @@ void unit_ref_unset(UnitRef *ref) {
         if (!ref->unit)
                 return;
 
+        /* We are about to drop a reference to the unit, make sure the garbage collection has a look at it as it might
+         * be unreferenced now. */
+        unit_add_to_gc_queue(ref->unit);
+
         LIST_REMOVE(refs, ref->unit->refs, ref);
         ref->unit = NULL;
 }