From 756e28f04f1a36d27bf5c671a6ebfa0960141721 Mon Sep 17 00:00:00 2001
From: Tim Graham <timograham@gmail.com>
Date: Fri, 10 May 2024 17:55:58 -0400
Subject: [PATCH] fix QuerySet results when Q() conditions are empty or full

---
 .github/workflows/test-python.yml |  1 +
 django_mongodb/compiler.py        |  7 ++++--
 django_mongodb/features.py        |  2 --
 django_mongodb/query.py           | 38 ++++++++++++++++++++++++++++---
 4 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/test-python.yml b/.github/workflows/test-python.yml
index 831ef9d0..600f7fb9 100644
--- a/.github/workflows/test-python.yml
+++ b/.github/workflows/test-python.yml
@@ -77,6 +77,7 @@ jobs:
           lookup.tests.LookupQueryingTests.test_isnull_lookup_in_filter
           model_fields
           or_lookups
+          queries.tests.Ticket12807Tests.test_ticket_12807
           sessions_tests
           update
 
diff --git a/django_mongodb/compiler.py b/django_mongodb/compiler.py
index 457ecad4..afeefd38 100644
--- a/django_mongodb/compiler.py
+++ b/django_mongodb/compiler.py
@@ -1,5 +1,5 @@
 from django.conf import settings
-from django.core.exceptions import EmptyResultSet
+from django.core.exceptions import EmptyResultSet, FullResultSet
 from django.db import (
     DatabaseError,
     IntegrityError,
@@ -128,7 +128,10 @@ def build_query(self, columns=None):
         self.check_query()
         self.setup_query()
         query = self.query_class(self, columns)
-        query.add_filters(self.query.where)
+        try:
+            query.add_filters(self.query.where)
+        except FullResultSet:
+            query.mongo_query = []
         query.order_by(self._get_ordering())
 
         # This at least satisfies the most basic unit tests.
diff --git a/django_mongodb/features.py b/django_mongodb/features.py
index 2e70ee35..20093e33 100644
--- a/django_mongodb/features.py
+++ b/django_mongodb/features.py
@@ -34,8 +34,6 @@ class DatabaseFeatures(BaseDatabaseFeatures):
         # 'TruncDate' object has no attribute 'alias'
         "model_fields.test_datetimefield.DateTimeFieldTests.test_lookup_date_with_use_tz",
         "model_fields.test_datetimefield.DateTimeFieldTests.test_lookup_date_without_use_tz",
-        # Empty queryset ORed (|) with another gives empty results.
-        "or_lookups.tests.OrLookupsTests.test_empty_in",
     }
 
     django_test_skips = {
diff --git a/django_mongodb/query.py b/django_mongodb/query.py
index b5d51e3d..9b40d143 100644
--- a/django_mongodb/query.py
+++ b/django_mongodb/query.py
@@ -1,11 +1,11 @@
 import re
 from functools import wraps
 
-from django.core.exceptions import FullResultSet
+from django.core.exceptions import EmptyResultSet, FullResultSet
 from django.db import DatabaseError, IntegrityError, NotSupportedError
 from django.db.models.lookups import UUIDTextMixin
 from django.db.models.query import QuerySet
-from django.db.models.sql.where import OR, SubqueryConstraint
+from django.db.models.sql.where import AND, OR, SubqueryConstraint
 from django.utils.tree import Node
 from pymongo import ASCENDING, DESCENDING
 from pymongo.errors import DuplicateKeyError, PyMongoError
@@ -142,6 +142,11 @@ def get_cursor(self):
     def add_filters(self, filters, query=None):
         children = self._get_children(filters.children)
 
+        if filters.connector == AND:
+            full_needed, empty_needed = len(children), 1
+        else:
+            full_needed, empty_needed = 1, len(children)
+
         if query is None:
             query = self.mongo_query
 
@@ -162,7 +167,20 @@ def add_filters(self, filters, query=None):
                 if filters.connector == OR and filters.negated:
                     raise NotImplementedError("Negated ORs are not supported.")
 
-                self.add_filters(child, query=subquery)
+                try:
+                    self.add_filters(child, query=subquery)
+                except EmptyResultSet:
+                    empty_needed -= 1
+                    if empty_needed == 0:
+                        exc = FullResultSet if filters.negated else EmptyResultSet
+                        raise exc from None
+                    continue
+                except FullResultSet:
+                    full_needed -= 1
+                    if full_needed == 0:
+                        exc = EmptyResultSet if filters.negated else FullResultSet
+                        raise exc from None
+                    continue
 
                 if filters.connector == OR and subquery:
                     or_conditions.extend(subquery.pop("$or", []))
@@ -173,7 +191,21 @@ def add_filters(self, filters, query=None):
 
             try:
                 field, lookup_type, value = self._decode_child(child)
+            except EmptyResultSet:
+                empty_needed -= 1
+                if empty_needed == 0:
+                    if filters.negated:
+                        self._negated = not self._negated
+                    exc = FullResultSet if filters.negated else EmptyResultSet
+                    raise exc from None
+                continue
             except FullResultSet:
+                full_needed -= 1
+                if full_needed == 0:
+                    if filters.negated:
+                        self._negated = not self._negated
+                    exc = EmptyResultSet if filters.negated else FullResultSet
+                    raise exc from None
                 continue
 
             column = field.column