FA-28396 / HTTP redirects / Open access
Cache redirects only under the stipulated freshness and response policy: permanent class · case 01
Cache redirects only under the stipulated freshness and response policy: the permanent class branch emits an incorrect decision.
ROOT CAUSE
The permanent-class decision uses 'status == 301'; this violates the stipulated controller policy.
VERIFIED REPAIR
At this decision use 'status in (301,308)', preserving the other controller outputs.
Unsuccessful approach: The partial repair uses 'status in (301,302,308)' 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 == 301, 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, False, 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'} | Failed |
| 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 / 9a2f4cc9128d8416ca60ec5de63bab1fe0e8313d587e983aadb6cb6efe26aca6
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 (301,302,308), 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, True, 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'} | 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 / 54fa2f7ee44d77c677a038f633215406de5c1999140f68888d0e63f5a0c4045a
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 2026-09-29T14:41:33.562381+00:00.
Case digest / fcdb103593976b8bc179beffe1af35c2b46d037a7bdb325784efe5db7443aa7f