FA-6741 / HTTP caching / Open access

Request min fresh reserves future freshness · case 01

Request min fresh reserves future freshness.

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

ROOT CAUSE

The faulty implementation uses `age < life` for the request-min-fresh-reserves-future-freshness decision.

VERIFIED REPAIR

Apply the explicit request-min-fresh-reserves-future-freshness contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `age+reserve <= life` and still violates a separate fixture.

Case contract

Bounded offline decision model: request min fresh reserves future freshness. 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 request-min-fresh-reserves-future-freshness 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(age, life, reserve):
    return age < life
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(8, 10, 2), False)", "check('fixture 2', solve(8, 10, 3), False)", "check('fixture 3', solve(8, 10, 1), True)", "check('fixture 4', solve(0, 10, 0), True)"]
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	`True`	`False`	Failed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`True`	`False`	Failed

SHA-256 / 427f4890588e3f493329140ad66e42eb20d8dad9e286b62a80092aa739f2fd0a

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(age, life, reserve):
    return age+reserve <= life
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(8, 10, 2), False)", "check('fixture 2', solve(8, 10, 3), False)", "check('fixture 3', solve(8, 10, 1), True)", "check('fixture 4', solve(0, 10, 0), True)"]
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	`False`	`False`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`True`	`False`	Failed

SHA-256 / ff3f16280e4ec11caf2077fc67d83f49e25fb6492a24b29008d87e6fb7b580f3

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(age, life, reserve):
    return age+reserve < life
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(8, 10, 2), False)", "check('fixture 2', solve(8, 10, 3), False)", "check('fixture 3', solve(8, 10, 1), True)", "check('fixture 4', solve(0, 10, 0), True)"]
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	`False`	`False`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`False`	`False`	Passed

SHA-256 / e038bb526eed7659ca5ceac16b4b77aa7a419836cd60d67f0e00a7c80a3a5ec3

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 2026-09-29T14:38:04.849317+00:00.

Case digest / 78d25a94318d19dd809cc8c2c89d10ade31aef703ba67886513d121031c97ab1