FA-29121 / HTTP redirects / Open access

Canonicalize a directory URL after resource lookup without redirecting regular files: lookup before canonicalization · case 01

Canonicalize a directory URL after resource lookup without redirecting regular files: the lookup before canonicalization branch emits an incorrect decision.

Verified by executionVariant 1 · 7 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The lookup-before-canonicalization decision uses 'directory'; this violates the stipulated controller policy.

THE FAILURE

The lookup-before-canonicalization decision uses 'directory'; this violates the stipulated controller policy.

Unsuccessful approach: The partial repair uses 'exists or directory' and still fails an explicit boundary or control.

Case contract

Canonicalize a directory URL after resource lookup without redirecting regular files. 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, path, directory, exists, query, index_name, served):
    return {'request': request, 'decision': [directory and exists and not path.endswith('/'), path if path.endswith('/') else path+'/', path+('?' + query if query else ''), path.rsplit('/',1)[-1] == index_name, path.rsplit('/',1)[0]+'/', not served, directory, path or '/', path.rsplit('/',1)[-1], path.rstrip('/')+'/'+index_name]} 
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', '/docs', True, True, 'lang=en', 'index.html', False), {'request': '/requests/' + str(N) + '/0', 'decision': [True, '/docs/', '/docs?lang=en', False, '/', True, True, '/docs', 'docs', '/docs/index.html']})
check('fixture 2', solve('/requests/' + str(N) + '/1', '/docs/', True, True, '', 'index.html', False), {'request': '/requests/' + str(N) + '/1', 'decision': [False, '/docs/', '/docs/', False, '/docs/', True, True, '/docs/', '', '/docs/index.html']})
check('fixture 3', solve('/requests/' + str(N) + '/2', '/file.txt', False, True, 'v=1', 'index.html', True), {'request': '/requests/' + str(N) + '/2', 'decision': [False, '/file.txt/', '/file.txt?v=1', False, '/', False, True, '/file.txt', 'file.txt', '/file.txt/index.html']})
check('fixture 4', solve('/requests/' + str(N) + '/3', '/missing', True, False, 'x=', 'home.html', False), {'request': '/requests/' + str(N) + '/3', 'decision': [False, '/missing/', '/missing?x=', False, '/', True, False, '/missing', 'missing', '/missing/home.html']})
check('fixture 5', solve('/requests/' + str(N) + '/4', '/', True, True, '', 'index.html', True), {'request': '/requests/' + str(N) + '/4', 'decision': [False, '/', '/', False, '/', False, True, '/', '', '/index.html']})
check('fixture 6', solve('/requests/' + str(N) + '/5', '/docs/index.html', False, True, 'q=1', 'index.html', False), {'request': '/requests/' + str(N) + '/5', 'decision': [False, '/docs/index.html/', '/docs/index.html?q=1', True, '/docs/', True, True, '/docs/index.html', 'index.html', '/docs/index.html/index.html']})
check('fixture 7', solve('/requests/' + str(N) + '/6', '/index.html/other.html', False, True, '', 'index.html', False), {'request': '/requests/' + str(N) + '/6', 'decision': [False, '/index.html/other.html/', '/index.html/other.html', False, '/index.html/', True, True, '/index.html/other.html', 'other.html', '/index.html/other.html/index.html']})
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': [True, '/docs/', '/docs?lang=en', False, '/', True, True, '/docs', 'docs', '/docs/index.html'], 'request': '/requests/1/0'}`	`{'decision': [True, '/docs/', '/docs?lang=en', False, '/', True, True, '/docs', 'docs', '/docs/index.html'], 'request': '/requests/1/0'}`	Passed
fixture 2	`{'decision': [False, '/docs/', '/docs/', False, '/docs/', True, True, '/docs/', '', '/docs/index.html'], 'request': '/requests/1/1'}`	`{'decision': [False, '/docs/', '/docs/', False, '/docs/', True, True, '/docs/', '', '/docs/index.html'], 'request': '/requests/1/1'}`	Passed
fixture 3	`{'decision': [False, '/file.txt/', '/file.txt?v=1', False, '/', False, False, '/file.txt', 'file.txt', '/file.txt/index.html'], 'request': '/requests/1/2'}`	`{'decision': [False, '/file.txt/', '/file.txt?v=1', False, '/', False, True, '/file.txt', 'file.txt', '/file.txt/index.html'], 'request': '/requests/1/2'}`	Failed
fixture 4	`{'decision': [False, '/missing/', '/missing?x=', False, '/', True, True, '/missing', 'missing', '/missing/home.html'], 'request': '/requests/1/3'}`	`{'decision': [False, '/missing/', '/missing?x=', False, '/', True, False, '/missing', 'missing', '/missing/home.html'], 'request': '/requests/1/3'}`	Failed
fixture 5	`{'decision': [False, '/', '/', False, '/', False, True, '/', '', '/index.html'], 'request': '/requests/1/4'}`	`{'decision': [False, '/', '/', False, '/', False, True, '/', '', '/index.html'], 'request': '/requests/1/4'}`	Passed
fixture 6	`{'decision': [False, '/docs/index.html/', '/docs/index.html?q=1', True, '/docs/', True, False, '/docs/index.html', 'index.html', '/docs/index.html/index.html'], 'request': '/requests/1/5'}`	`{'decision': [False, '/docs/index.html/', '/docs/index.html?q=1', True, '/docs/', True, True, '/docs/index.html', 'index.html', '/docs/index.html/index.html'], 'request': '/requests/1/5'}`	Failed
fixture 7	`{'decision': [False, '/index.html/other.html/', '/index.html/other.html', False, '/index.html/', True, False, '/index.html/other.html', 'other.html', '/index.html/other.html/index.html'], 'request': '/requests/1/6'}`	`{'decision': [False, '/index.html/other.html/', '/index.html/other.html', False, '/index.html/', True, True, '/index.html/other.html', 'other.html', '/index.html/other.html/index.html'], 'request': '/requests/1/6'}`	Failed

SHA-256 / 44973ee4a10c7783ccefe4eecd5f0b3165cc7d3595b7ea980c6795799d84dc96

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, path, directory, exists, query, index_name, served):
    return {'request': request, 'decision': [directory and exists and not path.endswith('/'), path if path.endswith('/') else path+'/', path+('?' + query if query else ''), path.rsplit('/',1)[-1] == index_name, path.rsplit('/',1)[0]+'/', not served, exists or directory, path or '/', path.rsplit('/',1)[-1], path.rstrip('/')+'/'+index_name]} 
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', '/docs', True, True, 'lang=en', 'index.html', False), {'request': '/requests/' + str(N) + '/0', 'decision': [True, '/docs/', '/docs?lang=en', False, '/', True, True, '/docs', 'docs', '/docs/index.html']})
check('fixture 2', solve('/requests/' + str(N) + '/1', '/docs/', True, True, '', 'index.html', False), {'request': '/requests/' + str(N) + '/1', 'decision': [False, '/docs/', '/docs/', False, '/docs/', True, True, '/docs/', '', '/docs/index.html']})
check('fixture 3', solve('/requests/' + str(N) + '/2', '/file.txt', False, True, 'v=1', 'index.html', True), {'request': '/requests/' + str(N) + '/2', 'decision': [False, '/file.txt/', '/file.txt?v=1', False, '/', False, True, '/file.txt', 'file.txt', '/file.txt/index.html']})
check('fixture 4', solve('/requests/' + str(N) + '/3', '/missing', True, False, 'x=', 'home.html', False), {'request': '/requests/' + str(N) + '/3', 'decision': [False, '/missing/', '/missing?x=', False, '/', True, False, '/missing', 'missing', '/missing/home.html']})
check('fixture 5', solve('/requests/' + str(N) + '/4', '/', True, True, '', 'index.html', True), {'request': '/requests/' + str(N) + '/4', 'decision': [False, '/', '/', False, '/', False, True, '/', '', '/index.html']})
check('fixture 6', solve('/requests/' + str(N) + '/5', '/docs/index.html', False, True, 'q=1', 'index.html', False), {'request': '/requests/' + str(N) + '/5', 'decision': [False, '/docs/index.html/', '/docs/index.html?q=1', True, '/docs/', True, True, '/docs/index.html', 'index.html', '/docs/index.html/index.html']})
check('fixture 7', solve('/requests/' + str(N) + '/6', '/index.html/other.html', False, True, '', 'index.html', False), {'request': '/requests/' + str(N) + '/6', 'decision': [False, '/index.html/other.html/', '/index.html/other.html', False, '/index.html/', True, True, '/index.html/other.html', 'other.html', '/index.html/other.html/index.html']})
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': [True, '/docs/', '/docs?lang=en', False, '/', True, True, '/docs', 'docs', '/docs/index.html'], 'request': '/requests/1/0'}`	`{'decision': [True, '/docs/', '/docs?lang=en', False, '/', True, True, '/docs', 'docs', '/docs/index.html'], 'request': '/requests/1/0'}`	Passed
fixture 2	`{'decision': [False, '/docs/', '/docs/', False, '/docs/', True, True, '/docs/', '', '/docs/index.html'], 'request': '/requests/1/1'}`	`{'decision': [False, '/docs/', '/docs/', False, '/docs/', True, True, '/docs/', '', '/docs/index.html'], 'request': '/requests/1/1'}`	Passed
fixture 3	`{'decision': [False, '/file.txt/', '/file.txt?v=1', False, '/', False, True, '/file.txt', 'file.txt', '/file.txt/index.html'], 'request': '/requests/1/2'}`	`{'decision': [False, '/file.txt/', '/file.txt?v=1', False, '/', False, True, '/file.txt', 'file.txt', '/file.txt/index.html'], 'request': '/requests/1/2'}`	Passed
fixture 4	`{'decision': [False, '/missing/', '/missing?x=', False, '/', True, True, '/missing', 'missing', '/missing/home.html'], 'request': '/requests/1/3'}`	`{'decision': [False, '/missing/', '/missing?x=', False, '/', True, False, '/missing', 'missing', '/missing/home.html'], 'request': '/requests/1/3'}`	Failed
fixture 5	`{'decision': [False, '/', '/', False, '/', False, True, '/', '', '/index.html'], 'request': '/requests/1/4'}`	`{'decision': [False, '/', '/', False, '/', False, True, '/', '', '/index.html'], 'request': '/requests/1/4'}`	Passed
fixture 6	`{'decision': [False, '/docs/index.html/', '/docs/index.html?q=1', True, '/docs/', True, True, '/docs/index.html', 'index.html', '/docs/index.html/index.html'], 'request': '/requests/1/5'}`	`{'decision': [False, '/docs/index.html/', '/docs/index.html?q=1', True, '/docs/', True, True, '/docs/index.html', 'index.html', '/docs/index.html/index.html'], 'request': '/requests/1/5'}`	Passed
fixture 7	`{'decision': [False, '/index.html/other.html/', '/index.html/other.html', False, '/index.html/', True, True, '/index.html/other.html', 'other.html', '/index.html/other.html/index.html'], 'request': '/requests/1/6'}`	`{'decision': [False, '/index.html/other.html/', '/index.html/other.html', False, '/index.html/', True, True, '/index.html/other.html', 'other.html', '/index.html/other.html/index.html'], 'request': '/requests/1/6'}`	Passed

SHA-256 / db5fb61fce5b715ec68653ece5c9148e480019228045ed3caa073e9204b20912

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 7 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

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 2026-09-29T14:41:40.293118+00:00.

Case digest / 3ae89be51e0c0bc63cb29c9e4068add7761d754dca1f8495f10ae5b667eaacba