fix(octopus): count a GraphQL body of data null as a failure for the log gate, and correct its comment

A body of data null with no errors key returns None to the caller, which then reports the query
as failed, but the gate treated it as a success and logged a repeat briefly without the request.
Count a missing or null data value as a failure. The comment also claimed every gated failure
returns no data; a partial error returned with data under ignore_errors is logged in full too,
so say so.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: chalfontchubby

apps/predbat/octopus.py

@@ -2394,9 +2394,9 @@ def log_request_beside_failure():
                 # Process response (which reads the text)
                 response_body = await self.async_read_response_retry(response, url, ignore_errors=ignore_errors)
                 body_text = str(response_body)
-                # A failure is anything the code below will not return data for: a bad status, an errors key, or a
-                # body that is missing (unreadable JSON, a rate limit) or has no data
-                failed = response.status != 200 or not isinstance(response_body, dict) or "errors" in response_body or "data" not in response_body
+                # Logged in full with its request: a bad status, a body that is missing (unreadable JSON, a rate limit)
+                # or has no data, or any errors key - even a partial error returned with data when ignore_errors is set
+                failed = response.status != 200 or not isinstance(response_body, dict) or "errors" in response_body or response_body.get("data") is None
                 if failed:
                     log_request_beside_failure()
                 self.log_gate.log(

apps/predbat/tests/test_octopus_logging.py

@@ -139,7 +139,7 @@ async def test_octopus_logging(my_predbat):
 
     # A status 200 with no usable body (unreadable JSON, a rate limit) or no data is a failure too: the request and
     # the response are logged in full beside it, even when they repeat
-    for bad_body, context in [(None, "test-no-body"), ({"other": 1}, "test-no-data")]:
+    for bad_body, context in [(None, "test-no-body"), ({"other": 1}, "test-no-data"), ({"data": None}, "test-null-data")]:
         api.async_read_response_retry = AsyncMock(return_value=bad_body)
         await api.async_graphql_query("query { empty }", context, returns_data=True)
         log_lines.clear()