Fix User.current_galaxy_session

lib/galaxy/model/__init__.py

@@ -10761,7 +10761,9 @@ User.preferences = association_proxy("_preferences", "value", creator=UserPrefer
 # See https://github.com/sqlalchemy/sqlalchemy/discussions/7638 for approach
 session_partition = select(
     GalaxySession,
-    func.row_number().over(order_by=GalaxySession.update_time, partition_by=GalaxySession.user_id).label("index"),
+    func.row_number()
+    .over(order_by=GalaxySession.update_time.desc(), partition_by=GalaxySession.user_id)
+    .label("index"),
 ).alias()
 partitioned_session = aliased(GalaxySession, session_partition)
 User.current_galaxy_session = relationship(

test/unit/data/test_galaxy_mapping.py

@@ -698,6 +698,17 @@ class TestMappings(BaseModelTestCase):
         session.add(lf)
         session.flush()
 
+    def test_current_session(self):
+        user = model.User(email="testworkflows@bx.psu.edu", password="password")
+        galaxy_session = model.GalaxySession()
+        galaxy_session.user = user
+        self.persist(user, galaxy_session)
+        assert user.current_galaxy_session == galaxy_session
+        new_galaxy_session = model.GalaxySession()
+        new_galaxy_session.user = user
+        self.persist(user, new_galaxy_session)
+        assert user.current_galaxy_session == new_galaxy_session
+
     def test_flush_refreshes(self):
         # Normally I don't believe in unit testing library code, but the behaviors around attribute
         # states and flushing in SQL Alchemy is very subtle and it is good to have a executable