Fix LiveServer for in-memory SQLite database

`allow_thread_sharing` is no longer writeable since Django 2.2.

Author: Michael Howitz

AUTHORS

@@ -14,3 +14,4 @@ Donald Stufft <donald@stufft.io>
 Nicolas Delaby <ticosax@free.fr>
 Daniel Hahler <https://twitter.com/blueyed>
 Hasan Ramezani <hasan.r67@gmail.com>
+Michael Howitz

docs/changelog.rst

@@ -1,6 +1,16 @@
 Changelog
 =========
 
+unreleased
+----------
+
+Bugfixes
+^^^^^^^^
+
+* Fix :fixture:`live_server` when using an in-memory SQLite database on
+  Django >= 3.0.
+
+
 v4.4.0 (2021-06-06)
 -------------------
 

pytest_django/live_server_helper.py

@@ -24,7 +24,7 @@ def __init__(self, addr: str) -> None:
                 and conn.settings_dict["NAME"] == ":memory:"
             ):
                 # Explicitly enable thread-shareability for this connection
-                conn.allow_thread_sharing = True
+                conn.inc_thread_sharing()
                 connections_override[conn.alias] = conn
 
         liveserver_kwargs["connections_override"] = connections_override
@@ -60,8 +60,12 @@ def __init__(self, addr: str) -> None:
 
     def stop(self) -> None:
         """Stop the server"""
+        # Terminate the live server's thread.
         self.thread.terminate()
         self.thread.join()
+        # Restore shared connections' non-shareability.
+        for conn in self.thread.connections_override.values():
+            conn.dec_thread_sharing()
 
     @property
     def url(self) -> str: