From 93a80c6580cdafce2f71aac386e91ae511f9dd9e Mon Sep 17 00:00:00 2001
From: jeremystretch <jstretch@netboxlabs.com>
Date: Fri, 17 Feb 2023 15:12:56 -0500
Subject: [PATCH] Use BooleanFilter for 'empty' lookups

---
 netbox/extras/lookups.py    | 14 +++++++++-----
 netbox/netbox/filtersets.py |  8 ++++++++
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/netbox/extras/lookups.py b/netbox/extras/lookups.py
index 7197efcfc..84d5406af 100644
--- a/netbox/extras/lookups.py
+++ b/netbox/extras/lookups.py
@@ -6,12 +6,16 @@ class Empty(Lookup):
     Filter on whether a string is empty.
     """
     lookup_name = 'empty'
+    prepare_rhs = False
 
-    def as_sql(self, qn, connection):
-        lhs, lhs_params = self.process_lhs(qn, connection)
-        rhs, rhs_params = self.process_rhs(qn, connection)
-        params = lhs_params + rhs_params
-        return 'CAST(LENGTH(%s) AS BOOLEAN) != %s' % (lhs, rhs), params
+    def as_sql(self, compiler, connection):
+        if not isinstance(self.rhs, bool):
+            raise ValueError("The QuerySet value for an empty lookup must be True or False.")
+        sql, params = compiler.compile(self.lhs)
+        if self.rhs:
+            return f"CAST(LENGTH({sql}) AS BOOLEAN) IS NOT TRUE", params
+        else:
+            return f"CAST(LENGTH({sql}) AS BOOLEAN) IS TRUE", params
 
 
 CharField.register_lookup(Empty)
diff --git a/netbox/netbox/filtersets.py b/netbox/netbox/filtersets.py
index ee0ab330c..62c85a515 100644
--- a/netbox/netbox/filtersets.py
+++ b/netbox/netbox/filtersets.py
@@ -224,6 +224,14 @@ class BaseFilterSet(django_filters.FilterSet):
 
         return filters
 
+    @classmethod
+    def filter_for_lookup(cls, field, lookup_type):
+
+        if lookup_type == 'empty':
+            return django_filters.BooleanFilter, {}
+
+        return super().filter_for_lookup(field, lookup_type)
+
 
 class ChangeLoggedModelFilterSet(BaseFilterSet):
     """