[pasmud]

Calling URL.get_decoded_url(lazy=True) caches a wrapper without decoding its fields. A later eager get_decoded_url() returns that wrapper without validation, so an invalid UTF-8 path such as https://example.com/%FF succeeds even though a fresh eager call raises UnicodeDecodeError.

Validate the cached wrapper's fields on eager calls, preserving its identity and lazy access. Two regression tests cover invalid UTF-8 across URL components, repeated eager failures and reuse of a valid cached wrapper.

Validation on Windows/Python3.13.1: 137 tests passed, including doctests and Hypothesis tests, with one existing Hypothesis deprecation warning. Both new regression methods fail before the fix. Black21.7b0 checks and git diff --check pass. Modern Flake8 reports the same ten diagnostics on the patch and unchanged source. The full tox matrix and other Python versions remain unverified.