django32: change the way Thread are made tenant aware (#67760)

Django 3.2. changed the implementation of django.db.ConnectionHandler it
now uses asgiref.local.Local as a thread/asyncio-task local dictionnary
instead of threading.local. This new implementation use
threading.current_thread() to get a reference to the current thread
instead of threading._get_ident(), but inside __bootstrap_inner, the
_active dictionnary is not initialized and current_thread() returns a
dummy value instead of the current thread.

To work around this behaviour I made __bootstrap_inner wrap the run
method with the code needed to setup the tenant, so that it's run after
__boostrap_inner initialization of the current thread in the _active
dictionnary.

hobo/multitenant/threads.py

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import functools
 import threading
 
 _Thread_start = threading.Thread.start
@@ -28,21 +29,34 @@ def _new_start(self):
     return _Thread_start(self)
 
 
+def wrap_run(self, func):
+    if getattr(func, '_wrapped', False):
+        return func
+
+    @functools.wraps(func)
+    def wrapper():
+        tenant = getattr(self, 'tenant', None)
+
+        if tenant is not None:
+            from django.db import connection
+
+            old_tenant = connection.tenant
+            connection.set_tenant(self.tenant)
+            try:
+                func()
+            finally:
+                connection.set_tenant(old_tenant)
+                connection.close()
+        else:
+            func()
+
+    wrapper._wrapped = True
+    return wrapper
+
+
 def _new__bootstrap_inner(self):
-    tenant = getattr(self, 'tenant', None)
-
-    if tenant is not None:
-        from django.db import connection
-
-        old_tenant = connection.tenant
-        connection.set_tenant(self.tenant)
-        try:
-            _Thread__bootstrap_inner(self)
-        finally:
-            connection.set_tenant(old_tenant)
-            connection.close()
-    else:
-        _Thread__bootstrap_inner(self)
+    self.run = wrap_run(self, self.run)
+    _Thread__bootstrap_inner(self)
 
 
 def install_tenant_aware_threads():