Update endpoints of circuit terminations without creating a loop

Reverts "Break infinite loop by removing redundant update"

netbox/circuits/signals.py

@@ -1,4 +1,4 @@
-from django.db.models.signals import post_delete, post_save
+from django.db.models.signals import post_delete, post_save, pre_delete
 from django.dispatch import receiver
 from django.utils import timezone
 
@@ -16,3 +16,18 @@ def update_circuit(instance, **kwargs):
     for circuit in circuits:
         circuit.last_updated = time
         circuit.save()
+
+
+@receiver(post_save, sender=CircuitTermination)
+def update_connected_endpoints(instance, created, **kwargs):
+    if created:
+        # Update all endpoints affected by this circuit
+        endpoints = instance.circuit.get_related_endpoints()
+        update_endpoints(endpoints)
+
+
+@receiver(post_delete, sender=CircuitTermination)
+def nullify_connected_endpoints(instance, **kwargs):
+    # Update all endpoints affected by this circuit (through the other termination point)
+    endpoints = instance.circuit.get_related_endpoints()
+    update_endpoints(endpoints)