fix(circuits): Require termination object for selected type

Require a Circuit Termination target when a termination type has been
selected, so blank dynamic target fields surface an inline form error
instead of falling through to generic GFK validation for termination_id.

Add a model-level guard for the same invalid state before generic
GenericForeignKey validation runs.

Fixes #22163

netbox/circuits/forms/model_forms.py

@@ -1,6 +1,6 @@
 from django import forms
 from django.contrib.contenttypes.models import ContentType
-from django.core.exceptions import ObjectDoesNotExist
+from django.core.exceptions import ObjectDoesNotExist, ValidationError
 from django.utils.translation import gettext_lazy as _
 
 from circuits.choices import (
@@ -24,7 +24,7 @@ from utilities.forms.fields import (
 from utilities.forms.mixins import DistanceValidationMixin
 from utilities.forms.rendering import FieldSet, InlineFields, M2MAddRemoveFields
 from utilities.forms.widgets import DatePicker, HTMXSelect, NumberWithOptions
-from utilities.templatetags.builtins.filters import bettertitle
+from utilities.string import title
 
 __all__ = (
     'CircuitForm',
@@ -195,13 +195,11 @@ class CircuitTerminationForm(NetBoxModelForm):
     termination_type = ContentTypeChoiceField(
         queryset=ContentType.objects.filter(model__in=CIRCUIT_TERMINATION_TERMINATION_TYPES),
         widget=HTMXSelect(),
-        required=False,
         label=_('Termination type')
     )
     termination = DynamicModelChoiceField(
         label=_('Termination'),
         queryset=Site.objects.none(),  # Initial queryset
-        required=False,
         disabled=True,
         selector=True
     )
@@ -247,16 +245,28 @@ class CircuitTerminationForm(NetBoxModelForm):
                 self.fields['termination'].queryset = model.objects.all()
                 self.fields['termination'].widget.attrs['selector'] = model._meta.label_lower
                 self.fields['termination'].disabled = False
-                self.fields['termination'].label = _(bettertitle(model._meta.verbose_name))
+                self.fields['termination'].label = _(title(model._meta.verbose_name))
             except ObjectDoesNotExist:
                 pass
 
             if self.instance and termination_type_id != self.instance.termination_type_id:
                 self.initial['termination'] = None
+        else:
+            # Clear the initial termination value if termination_type is not set
+            self.initial['termination'] = None
 
     def clean(self):
         super().clean()
 
+        termination = self.cleaned_data.get('termination')
+        termination_type = self.cleaned_data.get('termination_type')
+        if termination_type and not termination:
+            raise ValidationError({
+                'termination': _('Please select a {termination_type}.').format(
+                    termination_type=_(title(termination_type.model_class()._meta.verbose_name))
+                )
+            })
+
         # Assign the selected termination (if any)
         self.instance.termination = self.cleaned_data.get('termination')
 
@@ -319,7 +329,7 @@ class CircuitGroupAssignmentForm(NetBoxModelForm):
                 self.fields['member'].queryset = model.objects.all()
                 self.fields['member'].widget.attrs['selector'] = model._meta.label_lower
                 self.fields['member'].disabled = False
-                self.fields['member'].label = _(bettertitle(model._meta.verbose_name))
+                self.fields['member'].label = _(title(model._meta.verbose_name))
             except ObjectDoesNotExist:
                 pass
 

netbox/circuits/models/circuits.py

@@ -17,6 +17,7 @@ from netbox.models.features import (
     TagsMixin,
 )
 from netbox.models.mixins import DistanceMixin
+from utilities.string import title
 
 from .base import BaseCircuitType
 
@@ -367,6 +368,13 @@ class CircuitTermination(
         return reverse('circuits:circuittermination', args=[self.pk])
 
     def clean(self):
+        if self.termination_type and not (self.termination or self.termination_id):
+            termination_type = self.termination_type.model_class()
+            raise ValidationError(
+                _("Please select a {termination_type}.").format(
+                    termination_type=_(title(termination_type._meta.verbose_name))
+                )
+            )
         super().clean()
 
         if self.termination is None:

netbox/circuits/tests/test_forms.py

@@ -0,0 +1,43 @@
+from django.contrib.contenttypes.models import ContentType
+from django.test import TestCase
+
+from circuits.forms import CircuitTerminationForm
+from circuits.models import Circuit, CircuitType, Provider, ProviderNetwork
+
+
+class CircuitTerminationFormTestCase(TestCase):
+    @classmethod
+    def setUpTestData(cls):
+        provider = Provider.objects.create(name='Provider 1', slug='provider-1')
+        circuit_type = CircuitType.objects.create(name='Circuit Type 1', slug='circuit-type-1')
+
+        cls.circuit = Circuit.objects.create(
+            cid='Circuit 1',
+            provider=provider,
+            type=circuit_type,
+        )
+        cls.provider_network = ProviderNetwork.objects.create(
+            name='Provider Network 1',
+            provider=provider,
+        )
+
+    def test_termination_required_when_termination_type_is_selected(self):
+        """
+        Selecting a termination type without a target object should report a
+        validation error against the visible form field.
+        """
+        provider_network_type = ContentType.objects.get_for_model(ProviderNetwork)
+
+        form = CircuitTerminationForm(
+            data={
+                'circuit': self.circuit.pk,
+                'term_side': 'A',
+                'termination_type': provider_network_type.pk,
+                'termination': '',
+            }
+        )
+
+        self.assertFalse(form.is_valid())
+        self.assertIn('termination', form.errors)
+        self.assertIn('Please select a Provider Network.', form.errors['termination'])
+        self.assertNotIn('termination_id', form.errors)

netbox/circuits/tests/test_models.py

@@ -1,3 +1,5 @@
+from django.contrib.contenttypes.models import ContentType
+from django.core.exceptions import NON_FIELD_ERRORS, ValidationError
 from django.test import TestCase
 
 from circuits.models import Circuit, CircuitTermination, CircuitType, Provider, ProviderNetwork
@@ -146,3 +148,21 @@ class CircuitTerminationTestCase(TestCase):
 
         # Cache should be cleared (SET_NULL behavior)
         self.assertIsNone(self.circuits[0].termination_a)
+
+    def test_termination_required_when_termination_type_is_selected(self):
+        """Model rejects type-without-target before generic GFK validation hits termination_id."""
+        provider_network_type = ContentType.objects.get_for_model(ProviderNetwork)
+
+        termination = CircuitTermination(
+            circuit=self.circuits[0],
+            term_side='A',
+            termination_type=provider_network_type,
+        )
+
+        with self.assertRaises(ValidationError) as cm:
+            termination.full_clean()
+
+        errors = cm.exception.message_dict
+        self.assertIn(NON_FIELD_ERRORS, errors)
+        self.assertIn('Please select a Provider Network.', errors[NON_FIELD_ERRORS])
+        self.assertNotIn('termination_id', errors)