main: Fix handling unlimited archiving run duration

main.py

@@ -510,8 +510,9 @@ def kcidb_archive(event, context):
     # Find the maximum timestamp of the data we need to fetch
     # We try to align all tables on a single time boundary
     until = min(
-        datetime.datetime.max if data_max_duration is None
-        else min_after + data_max_duration,
+        datetime.datetime.max.replace(tzinfo=datetime.timezone.utc)
+        if data_max_duration is None else
+        min_after + data_max_duration,
         op_now - data_min_age
     )
 

test_main.py

@@ -454,3 +454,19 @@ def gen_data(id, ts):
             for obj in dump.get(obj_list_name, []))
         for obj_list_name in op_schema.id_fields
     ), "No complete three-week old data in the archive"
+
+    # Empty the archive
+    ar_client.empty()
+    # Trigger a run of full archiving at once, and wait
+    del params["data_max_duration"]
+    publisher.publish(params)
+    time.sleep(60)
+    # Check both data_4w and data_3w are in the archive database
+    dump = ar_client.dump()
+    assert all(
+        any(obj["id"] == "archive:4w"
+            for obj in dump.get(obj_list_name, [])) and
+        any(obj["id"] == "archive:3w"
+            for obj in dump.get(obj_list_name, []))
+        for obj_list_name in op_schema.id_fields
+    ), "No complete four- and three-week old data in the archive"