From 1a25f5a7f255ad332a6e4bfa43cb97294565c215 Mon Sep 17 00:00:00 2001
From: Jeremy Stretch <stretch@packetlife.net>
Date: Thu, 30 Jan 2020 15:12:10 -0500
Subject: [PATCH] Fixes #4030: Fix exception when bulk editing interfaces
 (revised)

---
 docs/release-notes/version-2.7.md       |  1 +
 netbox/dcim/models/device_components.py |  2 +-
 netbox/utilities/views.py               | 28 ++++++++++++++++++-------
 3 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/docs/release-notes/version-2.7.md b/docs/release-notes/version-2.7.md
index 196c041c5..ba33e062c 100644
--- a/docs/release-notes/version-2.7.md
+++ b/docs/release-notes/version-2.7.md
@@ -6,6 +6,7 @@
 
 ## Bug Fixes
 
+* [#4030](https://github.com/netbox-community/netbox/issues/4030) - Fix exception when bulk editing interfaces (revised)
 * [#4043](https://github.com/netbox-community/netbox/issues/4043) - Fix toggling of required fields in custom scripts
 * [#4049](https://github.com/netbox-community/netbox/issues/4049) - Restore missing `tags` field in IPAM service serializer
 * [#4052](https://github.com/netbox-community/netbox/issues/4052) - Fix error when bulk importing interfaces to virtual machines
diff --git a/netbox/dcim/models/device_components.py b/netbox/dcim/models/device_components.py
index 68bab8037..e37569f79 100644
--- a/netbox/dcim/models/device_components.py
+++ b/netbox/dcim/models/device_components.py
@@ -676,7 +676,7 @@ class Interface(CableTermination, ComponentModel):
             self.untagged_vlan = None
 
         # Only "tagged" interfaces may have tagged VLANs assigned. ("tagged all" implies all VLANs are assigned.)
-        if self.pk and self.mode is not InterfaceModeChoices.MODE_TAGGED:
+        if self.pk and self.mode != InterfaceModeChoices.MODE_TAGGED:
             self.tagged_vlans.clear()
 
         return super().save(*args, **kwargs)
diff --git a/netbox/utilities/views.py b/netbox/utilities/views.py
index d900a8545..88e5005bc 100644
--- a/netbox/utilities/views.py
+++ b/netbox/utilities/views.py
@@ -6,7 +6,7 @@ from django.contrib import messages
 from django.contrib.contenttypes.models import ContentType
 from django.core.exceptions import ValidationError
 from django.db import transaction, IntegrityError
-from django.db.models import Count, ProtectedError
+from django.db.models import Count, ManyToManyField, ProtectedError
 from django.db.models.query import QuerySet
 from django.forms import CharField, Form, ModelMultipleChoiceField, MultipleHiddenInput, Textarea
 from django.http import HttpResponse, HttpResponseServerError
@@ -650,7 +650,9 @@ class BulkEditView(GetReturnURLMixin, View):
             if form.is_valid():
 
                 custom_fields = form.custom_fields if hasattr(form, 'custom_fields') else []
-                standard_fields = [field for field in form.fields if field not in custom_fields and field != 'pk']
+                standard_fields = [
+                    field for field in form.fields if field not in custom_fields + ['pk', 'add_tags', 'remove_tags']
+                ]
                 nullified_fields = request.POST.getlist('_nullify')
 
                 try:
@@ -662,14 +664,24 @@ class BulkEditView(GetReturnURLMixin, View):
 
                             # Update standard fields. If a field is listed in _nullify, delete its value.
                             for name in standard_fields:
-                                if name in form.nullable_fields and name in nullified_fields and isinstance(form.cleaned_data[name], QuerySet):
-                                    getattr(obj, name).set([])
-                                elif name in form.nullable_fields and name in nullified_fields:
-                                    setattr(obj, name, '' if isinstance(form.fields[name], CharField) else None)
-                                elif isinstance(form.cleaned_data[name], QuerySet) and form.cleaned_data[name]:
+
+                                model_field = model._meta.get_field(name)
+
+                                # Handle nullification
+                                if name in form.nullable_fields and name in nullified_fields:
+                                    if isinstance(model_field, ManyToManyField):
+                                        getattr(obj, name).set([])
+                                    else:
+                                        setattr(obj, name, None if model_field.null else '')
+
+                                # ManyToManyFields
+                                elif isinstance(model_field, ManyToManyField):
                                     getattr(obj, name).set(form.cleaned_data[name])
-                                elif form.cleaned_data[name] not in (None, '') and not isinstance(form.cleaned_data[name], QuerySet):
+
+                                # Normal fields
+                                elif form.cleaned_data[name] not in (None, ''):
                                     setattr(obj, name, form.cleaned_data[name])
+
                             obj.full_clean()
                             obj.save()