FA-28111 / HTTP redirects / Open access
Commit redirect history only after target admission: failed hop retention · case 01
Commit redirect history only after target admission: the failed hop retention branch emits an incorrect decision.
ROOT CAUSE
The failed-hop-retention decision uses "{'completed':history+([pending] if not admitted else []),'rejected':None}"; this violates the stipulated controller policy.
VERIFIED REPAIR
At this decision use "{'completed':history,'rejected':None if admitted else pending}", preserving the other controller outputs.
Unsuccessful approach: The partial repair uses "{'completed':history,'rejected':pending}" and still fails an explicit boundary or control.
Case contract
Commit redirect history only after target admission. 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, history, pending, admitted, completed, terminal):
return {'request': request, 'decision': [history + ([pending] if admitted else []), history, pending if admitted else (history[-1] if history else None), completed and terminal, {'completed':history+([pending] if not admitted else []),'rejected':None}]}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', ['/z', '/a'], '/b', False, True, False), {'request': '/requests/' + str(N) + '/0', 'decision': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}]})
check('fixture 2', solve('/requests/' + str(N) + '/1', ['/z', '/a'], '/b', True, False, False), {'request': '/requests/' + str(N) + '/1', 'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}]})
check('fixture 3', solve('/requests/' + str(N) + '/2', [], '/a', True, True, True), {'request': '/requests/' + str(N) + '/2', 'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}]})
check('fixture 4', solve('/requests/' + str(N) + '/3', [], '/a', False, False, True), {'request': '/requests/' + str(N) + '/3', 'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}]})
check('fixture 5', solve('/requests/' + str(N) + '/4', ['/a'], '/b', False, False, False), {'request': '/requests/' + str(N) + '/4', 'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}]})
check('fixture 6', solve('/requests/' + str(N) + '/5', ['/b', '/a'], '/c', True, True, False), {'request': '/requests/' + str(N) + '/5', 'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}]})
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': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a', '/b'], 'rejected': None}], 'request': '/requests/1/0'} | {'decision': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}], 'request': '/requests/1/0'} | Failed |
| fixture 2 | {'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}], 'request': '/requests/1/1'} | {'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}], 'request': '/requests/1/1'} | Passed |
| fixture 3 | {'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}], 'request': '/requests/1/2'} | {'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}], 'request': '/requests/1/2'} | Passed |
| fixture 4 | {'decision': [[], [], None, False, {'completed': ['/a'], 'rejected': None}], 'request': '/requests/1/3'} | {'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}], 'request': '/requests/1/3'} | Failed |
| fixture 5 | {'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a', '/b'], 'rejected': None}], 'request': '/requests/1/4'} | {'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}], 'request': '/requests/1/4'} | Failed |
| fixture 6 | {'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}], 'request': '/requests/1/5'} | {'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}], 'request': '/requests/1/5'} | Passed |
SHA-256 / 6064c76f4de4e238d4e86b7a00ae514795e5c52b7a440cbbab629a82965c61e1
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, history, pending, admitted, completed, terminal):
return {'request': request, 'decision': [history + ([pending] if admitted else []), history, pending if admitted else (history[-1] if history else None), completed and terminal, {'completed':history,'rejected':pending}]}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', ['/z', '/a'], '/b', False, True, False), {'request': '/requests/' + str(N) + '/0', 'decision': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}]})
check('fixture 2', solve('/requests/' + str(N) + '/1', ['/z', '/a'], '/b', True, False, False), {'request': '/requests/' + str(N) + '/1', 'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}]})
check('fixture 3', solve('/requests/' + str(N) + '/2', [], '/a', True, True, True), {'request': '/requests/' + str(N) + '/2', 'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}]})
check('fixture 4', solve('/requests/' + str(N) + '/3', [], '/a', False, False, True), {'request': '/requests/' + str(N) + '/3', 'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}]})
check('fixture 5', solve('/requests/' + str(N) + '/4', ['/a'], '/b', False, False, False), {'request': '/requests/' + str(N) + '/4', 'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}]})
check('fixture 6', solve('/requests/' + str(N) + '/5', ['/b', '/a'], '/c', True, True, False), {'request': '/requests/' + str(N) + '/5', 'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}]})
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': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}], 'request': '/requests/1/0'} | {'decision': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}], 'request': '/requests/1/0'} | Passed |
| fixture 2 | {'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': '/b'}], 'request': '/requests/1/1'} | {'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}], 'request': '/requests/1/1'} | Failed |
| fixture 3 | {'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': '/a'}], 'request': '/requests/1/2'} | {'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}], 'request': '/requests/1/2'} | Failed |
| fixture 4 | {'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}], 'request': '/requests/1/3'} | {'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}], 'request': '/requests/1/3'} | Passed |
| fixture 5 | {'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}], 'request': '/requests/1/4'} | {'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}], 'request': '/requests/1/4'} | Passed |
| fixture 6 | {'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': '/c'}], 'request': '/requests/1/5'} | {'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}], 'request': '/requests/1/5'} | Failed |
SHA-256 / 5e7b205aef6016aa1d186436973edab7c263d7c4657a05b92a6017bd15b42271
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, history, pending, admitted, completed, terminal):
return {'request': request, 'decision': [history + ([pending] if admitted else []), history, pending if admitted else (history[-1] if history else None), completed and terminal, {'completed':history,'rejected':None if admitted else pending}]}
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', ['/z', '/a'], '/b', False, True, False), {'request': '/requests/' + str(N) + '/0', 'decision': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}]})
check('fixture 2', solve('/requests/' + str(N) + '/1', ['/z', '/a'], '/b', True, False, False), {'request': '/requests/' + str(N) + '/1', 'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}]})
check('fixture 3', solve('/requests/' + str(N) + '/2', [], '/a', True, True, True), {'request': '/requests/' + str(N) + '/2', 'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}]})
check('fixture 4', solve('/requests/' + str(N) + '/3', [], '/a', False, False, True), {'request': '/requests/' + str(N) + '/3', 'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}]})
check('fixture 5', solve('/requests/' + str(N) + '/4', ['/a'], '/b', False, False, False), {'request': '/requests/' + str(N) + '/4', 'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}]})
check('fixture 6', solve('/requests/' + str(N) + '/5', ['/b', '/a'], '/c', True, True, False), {'request': '/requests/' + str(N) + '/5', 'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}]})
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': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}], 'request': '/requests/1/0'} | {'decision': [['/z', '/a'], ['/z', '/a'], '/a', False, {'completed': ['/z', '/a'], 'rejected': '/b'}], 'request': '/requests/1/0'} | Passed |
| fixture 2 | {'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}], 'request': '/requests/1/1'} | {'decision': [['/z', '/a', '/b'], ['/z', '/a'], '/b', False, {'completed': ['/z', '/a'], 'rejected': None}], 'request': '/requests/1/1'} | Passed |
| fixture 3 | {'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}], 'request': '/requests/1/2'} | {'decision': [['/a'], [], '/a', True, {'completed': [], 'rejected': None}], 'request': '/requests/1/2'} | Passed |
| fixture 4 | {'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}], 'request': '/requests/1/3'} | {'decision': [[], [], None, False, {'completed': [], 'rejected': '/a'}], 'request': '/requests/1/3'} | Passed |
| fixture 5 | {'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}], 'request': '/requests/1/4'} | {'decision': [['/a'], ['/a'], '/a', False, {'completed': ['/a'], 'rejected': '/b'}], 'request': '/requests/1/4'} | Passed |
| fixture 6 | {'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}], 'request': '/requests/1/5'} | {'decision': [['/b', '/a', '/c'], ['/b', '/a'], '/c', False, {'completed': ['/b', '/a'], 'rejected': None}], 'request': '/requests/1/5'} | Passed |
SHA-256 / 7c4016924d9de385df3fde0fccc197c2874ccd548842afc4ce0e439973a9c749
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 2026-09-29T14:41:31.054077+00:00.
Case digest / eaec2165d7b8eceb4f7dcbba5141b870d5f4d2ff1ddfd923fba63a83119051d8