[coverage] Conformance findings: ERRORRECOV-014

[peco-engineer-bot]

Summary

Surfaced by the multi-language coverage fan-out while conformance-testing these SPEC-IDs against databricks/databricks-sql-python. Each finding is committed as an expected-failure (xfail) test in the coverage PR — the test asserts the CORRECT (post-fix) behavior and stays red until THIS driver (databricks/databricks-sql-python) is fixed, then flips green as a tripwire.

Findings

• ERRORRECOV-014 [sea]: kernel/SEA backend leaves the native/vendor error code unset (vendor_code is None) on both a SQL-layer failure and a pre-SQL auth failure, so the application sees an absent native error instead of the server's code or a documented generic default
  • failing test: test_server_native_error_code_propagation (see the coverage PR diff under tests/)

Reproduce & Expected

ERRORRECOV-014 — Verify that the server's native/vendor error code is propagated to the application's native-error field instead of being discarded in favour of the driver's generic code.

Reproduce:

SELECT * FROM does_not_exist_{unique_name}

Expected (per the shared spec):

• full assertion contract:

result:
- label: sql_layer_error
  error_native_code:
    not_equals: 0
- label: auth_failure
  error_native_code:
    not_equals: 0

Context

• The behavior was first fixed in a DIFFERENT driver — reference PR: https://github.com/databricks/databricks-odbc/pull/143 — which seeded the shared language-neutral spec. This issue tracks the same conformance gap in databricks/databricks-sql-python; the reference PR is for cross-referencing the intended behavior, NOT a change to this repo.
• Coverage PR carrying the reproducing xfail test(s): https://github.com/databricks/databricks-driver-test/pull/1148