FA-28401 / HTTP redirects / Open access
Cache redirects only under the stipulated freshness and response policy: explicit temporary freshness · case 01
Cache redirects only under the stipulated freshness and response policy: the explicit temporary freshness branch emits an incorrect decision.
ROOT CAUSE
The explicit-temporary-freshness decision uses 'status in (302,303,307)'; this violates the stipulated controller policy.
VERIFIED REPAIR
At this decision use 'status in (302,303,307) and ttl>0', preserving the other controller outputs.
Unsuccessful approach: The partial repair uses 'status == 302 and ttl>0' and still fails an explicit boundary or control.
Case contract
Cache redirects only under the stipulated freshness and response policy. The explicit fixture inputs and outputs define a bounded offline policy; request identity must accompany the decision.
Why this case matters
Models a redirect controller decision before following a target or exposing a redirect result.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
from urllib.parse import urlsplit, unquote, quote
import posixpath
import re
N = 1
observations = []
def solve(request, status, ttl, age, no_store, private, shared, location):
return {'request': request, 'decision': [max(0,ttl-age), status in (301,308), status in (302,303,307), not no_store, not (private and shared), age>=ttl, location is not None, status in (302,303,307) and ttl>age, age, status]}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', 301, 60, 10, False, False, True, '/b'), {'request': '/requests/' + str(N) + '/0', 'decision': [50, True, False, True, True, False, True, False, 10, 301]})
check('fixture 2', solve('/requests/' + str(N) + '/1', 302, 0, 0, False, False, True, '/c'), {'request': '/requests/' + str(N) + '/1', 'decision': [0, False, False, True, True, True, True, False, 0, 302]})
check('fixture 3', solve('/requests/' + str(N) + '/2', 307, 30, 35, False, True, True, '/d'), {'request': '/requests/' + str(N) + '/2', 'decision': [0, False, True, True, False, True, True, False, 35, 307]})
check('fixture 4', solve('/requests/' + str(N) + '/3', 308, 60, 0, True, False, False, '/e'), {'request': '/requests/' + str(N) + '/3', 'decision': [60, True, False, False, True, False, True, False, 0, 308]})
check('fixture 5', solve('/requests/' + str(N) + '/4', 303, 20, 5, False, True, False, ''), {'request': '/requests/' + str(N) + '/4', 'decision': [15, False, True, True, True, False, True, True, 5, 303]})
check('fixture 6', solve('/requests/' + str(N) + '/5', 200, 0, 0, False, False, False, None), {'request': '/requests/' + str(N) + '/5', 'decision': [0, False, False, True, True, True, False, False, 0, 200]})
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 1 | {'decision': [50, True, False, True, True, False, True, False, 10, 301], 'request': '/requests/1/0'} | {'decision': [50, True, False, True, True, False, True, False, 10, 301], 'request': '/requests/1/0'} | Passed |
| fixture 2 | {'decision': [0, False, True, True, True, True, True, False, 0, 302], 'request': '/requests/1/1'} | {'decision': [0, False, False, True, True, True, True, False, 0, 302], 'request': '/requests/1/1'} | Failed |
| fixture 3 | {'decision': [0, False, True, True, False, True, True, False, 35, 307], 'request': '/requests/1/2'} | {'decision': [0, False, True, True, False, True, True, False, 35, 307], 'request': '/requests/1/2'} | Passed |
| fixture 4 | {'decision': [60, True, False, False, True, False, True, False, 0, 308], 'request': '/requests/1/3'} | {'decision': [60, True, False, False, True, False, True, False, 0, 308], 'request': '/requests/1/3'} | Passed |
| fixture 5 | {'decision': [15, False, True, True, True, False, True, True, 5, 303], 'request': '/requests/1/4'} | {'decision': [15, False, True, True, True, False, True, True, 5, 303], 'request': '/requests/1/4'} | Passed |
| fixture 6 | {'decision': [0, False, False, True, True, True, False, False, 0, 200], 'request': '/requests/1/5'} | {'decision': [0, False, False, True, True, True, False, False, 0, 200], 'request': '/requests/1/5'} | Passed |
SHA-256 / f6274a206facb6cc68b1bc24410734075d10907ef7e18ddd7c7302f788718eda
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
from urllib.parse import urlsplit, unquote, quote
import posixpath
import re
N = 1
observations = []
def solve(request, status, ttl, age, no_store, private, shared, location):
return {'request': request, 'decision': [max(0,ttl-age), status in (301,308), status == 302 and ttl>0, not no_store, not (private and shared), age>=ttl, location is not None, status in (302,303,307) and ttl>age, age, status]}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', 301, 60, 10, False, False, True, '/b'), {'request': '/requests/' + str(N) + '/0', 'decision': [50, True, False, True, True, False, True, False, 10, 301]})
check('fixture 2', solve('/requests/' + str(N) + '/1', 302, 0, 0, False, False, True, '/c'), {'request': '/requests/' + str(N) + '/1', 'decision': [0, False, False, True, True, True, True, False, 0, 302]})
check('fixture 3', solve('/requests/' + str(N) + '/2', 307, 30, 35, False, True, True, '/d'), {'request': '/requests/' + str(N) + '/2', 'decision': [0, False, True, True, False, True, True, False, 35, 307]})
check('fixture 4', solve('/requests/' + str(N) + '/3', 308, 60, 0, True, False, False, '/e'), {'request': '/requests/' + str(N) + '/3', 'decision': [60, True, False, False, True, False, True, False, 0, 308]})
check('fixture 5', solve('/requests/' + str(N) + '/4', 303, 20, 5, False, True, False, ''), {'request': '/requests/' + str(N) + '/4', 'decision': [15, False, True, True, True, False, True, True, 5, 303]})
check('fixture 6', solve('/requests/' + str(N) + '/5', 200, 0, 0, False, False, False, None), {'request': '/requests/' + str(N) + '/5', 'decision': [0, False, False, True, True, True, False, False, 0, 200]})
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 1 | {'decision': [50, True, False, True, True, False, True, False, 10, 301], 'request': '/requests/1/0'} | {'decision': [50, True, False, True, True, False, True, False, 10, 301], 'request': '/requests/1/0'} | Passed |
| fixture 2 | {'decision': [0, False, False, True, True, True, True, False, 0, 302], 'request': '/requests/1/1'} | {'decision': [0, False, False, True, True, True, True, False, 0, 302], 'request': '/requests/1/1'} | Passed |
| fixture 3 | {'decision': [0, False, False, True, False, True, True, False, 35, 307], 'request': '/requests/1/2'} | {'decision': [0, False, True, True, False, True, True, False, 35, 307], 'request': '/requests/1/2'} | Failed |
| fixture 4 | {'decision': [60, True, False, False, True, False, True, False, 0, 308], 'request': '/requests/1/3'} | {'decision': [60, True, False, False, True, False, True, False, 0, 308], 'request': '/requests/1/3'} | Passed |
| fixture 5 | {'decision': [15, False, False, True, True, False, True, True, 5, 303], 'request': '/requests/1/4'} | {'decision': [15, False, True, True, True, False, True, True, 5, 303], 'request': '/requests/1/4'} | Failed |
| fixture 6 | {'decision': [0, False, False, True, True, True, False, False, 0, 200], 'request': '/requests/1/5'} | {'decision': [0, False, False, True, True, True, False, False, 0, 200], 'request': '/requests/1/5'} | Passed |
SHA-256 / e675f25f0e94763ff337925124103d42985f558b3f23f6fff61f51f7045ee00f
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
from urllib.parse import urlsplit, unquote, quote
import posixpath
import re
N = 1
observations = []
def solve(request, status, ttl, age, no_store, private, shared, location):
return {'request': request, 'decision': [max(0,ttl-age), status in (301,308), status in (302,303,307) and ttl>0, not no_store, not (private and shared), age>=ttl, location is not None, status in (302,303,307) and ttl>age, age, status]}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', 301, 60, 10, False, False, True, '/b'), {'request': '/requests/' + str(N) + '/0', 'decision': [50, True, False, True, True, False, True, False, 10, 301]})
check('fixture 2', solve('/requests/' + str(N) + '/1', 302, 0, 0, False, False, True, '/c'), {'request': '/requests/' + str(N) + '/1', 'decision': [0, False, False, True, True, True, True, False, 0, 302]})
check('fixture 3', solve('/requests/' + str(N) + '/2', 307, 30, 35, False, True, True, '/d'), {'request': '/requests/' + str(N) + '/2', 'decision': [0, False, True, True, False, True, True, False, 35, 307]})
check('fixture 4', solve('/requests/' + str(N) + '/3', 308, 60, 0, True, False, False, '/e'), {'request': '/requests/' + str(N) + '/3', 'decision': [60, True, False, False, True, False, True, False, 0, 308]})
check('fixture 5', solve('/requests/' + str(N) + '/4', 303, 20, 5, False, True, False, ''), {'request': '/requests/' + str(N) + '/4', 'decision': [15, False, True, True, True, False, True, True, 5, 303]})
check('fixture 6', solve('/requests/' + str(N) + '/5', 200, 0, 0, False, False, False, None), {'request': '/requests/' + str(N) + '/5', 'decision': [0, False, False, True, True, True, False, False, 0, 200]})
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 1 | {'decision': [50, True, False, True, True, False, True, False, 10, 301], 'request': '/requests/1/0'} | {'decision': [50, True, False, True, True, False, True, False, 10, 301], 'request': '/requests/1/0'} | Passed |
| fixture 2 | {'decision': [0, False, False, True, True, True, True, False, 0, 302], 'request': '/requests/1/1'} | {'decision': [0, False, False, True, True, True, True, False, 0, 302], 'request': '/requests/1/1'} | Passed |
| fixture 3 | {'decision': [0, False, True, True, False, True, True, False, 35, 307], 'request': '/requests/1/2'} | {'decision': [0, False, True, True, False, True, True, False, 35, 307], 'request': '/requests/1/2'} | Passed |
| fixture 4 | {'decision': [60, True, False, False, True, False, True, False, 0, 308], 'request': '/requests/1/3'} | {'decision': [60, True, False, False, True, False, True, False, 0, 308], 'request': '/requests/1/3'} | Passed |
| fixture 5 | {'decision': [15, False, True, True, True, False, True, True, 5, 303], 'request': '/requests/1/4'} | {'decision': [15, False, True, True, True, False, True, True, 5, 303], 'request': '/requests/1/4'} | Passed |
| fixture 6 | {'decision': [0, False, False, True, True, True, False, False, 0, 200], 'request': '/requests/1/5'} | {'decision': [0, False, False, True, True, True, False, False, 0, 200], 'request': '/requests/1/5'} | Passed |
SHA-256 / 25e7333f96ca6671ab42634b52c778ba3639040db566428c62f13fd5d61a9ef5
Verification & scope
Stipulated offline redirect policy, not a complete HTTP, browser, URL, cache, or security implementation. Numbered variants vary request correlation identity. 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 2026-09-29T14:41:33.602714+00:00.
Case digest / 185e7bf476a43f9cf35b453076f8eeb6a1989ac3691ce017b5da08f352c4bc2b