FA-6826 / HTTP caching / Open access

Cache warning removal preserves persistent warnings · case 01

Cache warning removal preserves persistent warnings.

Verified by executionVariant 1 · 4 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The faulty implementation uses `warnings` for the cache-warning-removal-preserves-persistent-warnings decision.

VERIFIED REPAIR

Apply the explicit cache-warning-removal-preserves-persistent-warnings contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `[]` and still violates a separate fixture.

Case contract

Bounded offline decision model: cache warning removal preserves persistent warnings. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.

Why this case matters

This deterministic http caching model isolates the cache-warning-removal-preserves-persistent-warnings policy at a network component boundary.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(warnings):
    return warnings
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve([110, 214]), [214])", "check('fixture 2', solve([199, 200]), [200])", "check('fixture 3', solve([]), [])", "check('fixture 4', solve([214, 299]), [214, 299])"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 2	`[199, 200]`	`[200]`	Failed
fixture 3	`[]`	`[]`	Passed
fixture 4	`[214, 299]`	`[214, 299]`	Passed
fixture 1	`[110, 214]`	`[214]`	Failed

SHA-256 / 8703726ce8f60cfee2b16d53bf35effdbef913487188e5133ff2d0e80b3b832c

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(warnings):
    return []
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve([110, 214]), [214])", "check('fixture 2', solve([199, 200]), [200])", "check('fixture 3', solve([]), [])", "check('fixture 4', solve([214, 299]), [214, 299])"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 2	`[]`	`[200]`	Failed
fixture 3	`[]`	`[]`	Passed
fixture 4	`[]`	`[214, 299]`	Failed
fixture 1	`[]`	`[214]`	Failed

SHA-256 / 7bffb7357f61e12c180cc0194fb54ad4edc8821ca0a8160276b8da28d61bce2c

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(warnings):
    return [w for w in warnings if not 100 <= w < 200]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve([110, 214]), [214])", "check('fixture 2', solve([199, 200]), [200])", "check('fixture 3', solve([]), [])", "check('fixture 4', solve([214, 299]), [214, 299])"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)

Boundary fixture	Actual	Expected	Outcome
fixture 2	`[200]`	`[200]`	Passed
fixture 3	`[]`	`[]`	Passed
fixture 4	`[214, 299]`	`[214, 299]`	Passed
fixture 1	`[214]`	`[214]`	Passed

SHA-256 / 49cf73de35807aad0f5d82a3062d2bcf1fd69c51328329cd70ac9999557dda32

Verification & scope

Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:38:05.581294+00:00.

Case digest / d259e10d1dba0f0ee84ad3b40a5780a68b965931f9acf41eb74d5e87b52b9d82