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FA-28786 / HTTP redirects / Open access

Commit a redirect chain using terminal document semantics and the original navigation intent: requested versus committed url · case 01

Commit a redirect chain using terminal document semantics and the original navigation intent: the requested versus committed url branch emits an incorrect decision.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The requested-versus-committed-url decision uses "{'requested':chain[-1],'committed':None if download else chain[-1]}"; this violates the stipulated controller policy.

VERIFIED REPAIR

At this decision use "{'requested':chain[0],'committed':None if download else chain[-1]}", preserving the other controller outputs.

Unsuccessful approach: The partial repair uses "{'requested':chain[0],'committed':chain[0]}" and still fails an explicit boundary or control.

Case contract

Commit a redirect chain using terminal document semantics and the original navigation intent. 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, chain, methods, state, download, activation, replace, initiator, allows):
    return {'request': request, 'decision': [[] if download else [chain[-1]], methods[-1] not in ('GET','HEAD'), state, 1 if activation else 0, replace, initiator, [u for u,ok in zip(chain,allows) if not ok], urlsplit(chain[-1]).netloc, 'download' if download else 'document', {'requested':chain[-1],'committed':None if download else chain[-1]}]} 
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', ['https://a/x', 'https://b/y', 'https://c/z'], ['POST', 'GET', 'GET'], {'view': 'v'}, False, True, False, 'https://start/home', [True, False, True]), {'request': '/requests/' + str(N) + '/0', 'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'requested': 'https://a/x', 'committed': 'https://c/z'}]})
check('fixture 2', solve('/requests/' + str(N) + '/1', ['https://a/x'], ['GET'], {'view': 'q'}, False, True, True, 'https://start/home', [True]), {'request': '/requests/' + str(N) + '/1', 'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'requested': 'https://a/x', 'committed': 'https://a/x'}]})
check('fixture 3', solve('/requests/' + str(N) + '/2', ['https://a/x', 'https://b/file'], ['GET', 'GET'], {}, True, False, False, 'https://start/a', [True, True]), {'request': '/requests/' + str(N) + '/2', 'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'requested': 'https://a/x', 'committed': None}]})
check('fixture 4', solve('/requests/' + str(N) + '/3', ['https://a/x', 'https://b/y'], ['POST', 'POST'], {'form': 'a'}, False, False, True, 'https://start/b', [False, True]), {'request': '/requests/' + str(N) + '/3', 'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'requested': 'https://a/x', 'committed': 'https://b/y'}]})
check('fixture 5', solve('/requests/' + str(N) + '/4', ['https://a/x', 'https://a/y'], ['GET', 'HEAD'], {}, False, True, False, 'https://start/c', [True, True]), {'request': '/requests/' + str(N) + '/4', 'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'requested': 'https://a/x', 'committed': 'https://a/y'}]})
check('fixture 6', solve('/requests/' + str(N) + '/5', ['https://a/x', 'https://b/file'], ['POST', 'GET'], {'download': 'd'}, True, True, True, 'https://start/d', [True, False]), {'request': '/requests/' + str(N) + '/5', 'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'requested': 'https://a/x', 'committed': 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 fixtureActualExpectedOutcome
fixture 1{'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'committed': 'https://c/z', 'requested': 'https://c/z'}], 'request': '/requests/1/0'}{'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'committed': 'https://c/z', 'requested': 'https://a/x'}], 'request': '/requests/1/0'}Failed
fixture 2{'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/1'}{'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/1'}Passed
fixture 3{'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'committed': None, 'requested': 'https://b/file'}], 'request': '/requests/1/2'}{'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/2'}Failed
fixture 4{'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'committed': 'https://b/y', 'requested': 'https://b/y'}], 'request': '/requests/1/3'}{'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'committed': 'https://b/y', 'requested': 'https://a/x'}], 'request': '/requests/1/3'}Failed
fixture 5{'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'committed': 'https://a/y', 'requested': 'https://a/y'}], 'request': '/requests/1/4'}{'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'committed': 'https://a/y', 'requested': 'https://a/x'}], 'request': '/requests/1/4'}Failed
fixture 6{'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'committed': None, 'requested': 'https://b/file'}], 'request': '/requests/1/5'}{'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/5'}Failed

SHA-256 / cab92837db4df911be3d4b69f6df0a068c1732f9d73991348c163acbb390f19c

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, chain, methods, state, download, activation, replace, initiator, allows):
    return {'request': request, 'decision': [[] if download else [chain[-1]], methods[-1] not in ('GET','HEAD'), state, 1 if activation else 0, replace, initiator, [u for u,ok in zip(chain,allows) if not ok], urlsplit(chain[-1]).netloc, 'download' if download else 'document', {'requested':chain[0],'committed':chain[0]}]} 
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', ['https://a/x', 'https://b/y', 'https://c/z'], ['POST', 'GET', 'GET'], {'view': 'v'}, False, True, False, 'https://start/home', [True, False, True]), {'request': '/requests/' + str(N) + '/0', 'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'requested': 'https://a/x', 'committed': 'https://c/z'}]})
check('fixture 2', solve('/requests/' + str(N) + '/1', ['https://a/x'], ['GET'], {'view': 'q'}, False, True, True, 'https://start/home', [True]), {'request': '/requests/' + str(N) + '/1', 'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'requested': 'https://a/x', 'committed': 'https://a/x'}]})
check('fixture 3', solve('/requests/' + str(N) + '/2', ['https://a/x', 'https://b/file'], ['GET', 'GET'], {}, True, False, False, 'https://start/a', [True, True]), {'request': '/requests/' + str(N) + '/2', 'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'requested': 'https://a/x', 'committed': None}]})
check('fixture 4', solve('/requests/' + str(N) + '/3', ['https://a/x', 'https://b/y'], ['POST', 'POST'], {'form': 'a'}, False, False, True, 'https://start/b', [False, True]), {'request': '/requests/' + str(N) + '/3', 'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'requested': 'https://a/x', 'committed': 'https://b/y'}]})
check('fixture 5', solve('/requests/' + str(N) + '/4', ['https://a/x', 'https://a/y'], ['GET', 'HEAD'], {}, False, True, False, 'https://start/c', [True, True]), {'request': '/requests/' + str(N) + '/4', 'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'requested': 'https://a/x', 'committed': 'https://a/y'}]})
check('fixture 6', solve('/requests/' + str(N) + '/5', ['https://a/x', 'https://b/file'], ['POST', 'GET'], {'download': 'd'}, True, True, True, 'https://start/d', [True, False]), {'request': '/requests/' + str(N) + '/5', 'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'requested': 'https://a/x', 'committed': 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 fixtureActualExpectedOutcome
fixture 1{'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/0'}{'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'committed': 'https://c/z', 'requested': 'https://a/x'}], 'request': '/requests/1/0'}Failed
fixture 2{'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/1'}{'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/1'}Passed
fixture 3{'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/2'}{'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/2'}Failed
fixture 4{'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/3'}{'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'committed': 'https://b/y', 'requested': 'https://a/x'}], 'request': '/requests/1/3'}Failed
fixture 5{'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/4'}{'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'committed': 'https://a/y', 'requested': 'https://a/x'}], 'request': '/requests/1/4'}Failed
fixture 6{'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/5'}{'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/5'}Failed

SHA-256 / 9f742b19ffaea5c9a0ba8154846d8584ae1020a070d914fe794c8cefb4df0716

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, chain, methods, state, download, activation, replace, initiator, allows):
    return {'request': request, 'decision': [[] if download else [chain[-1]], methods[-1] not in ('GET','HEAD'), state, 1 if activation else 0, replace, initiator, [u for u,ok in zip(chain,allows) if not ok], urlsplit(chain[-1]).netloc, 'download' if download else 'document', {'requested':chain[0],'committed':None if download else chain[-1]}]} 
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', ['https://a/x', 'https://b/y', 'https://c/z'], ['POST', 'GET', 'GET'], {'view': 'v'}, False, True, False, 'https://start/home', [True, False, True]), {'request': '/requests/' + str(N) + '/0', 'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'requested': 'https://a/x', 'committed': 'https://c/z'}]})
check('fixture 2', solve('/requests/' + str(N) + '/1', ['https://a/x'], ['GET'], {'view': 'q'}, False, True, True, 'https://start/home', [True]), {'request': '/requests/' + str(N) + '/1', 'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'requested': 'https://a/x', 'committed': 'https://a/x'}]})
check('fixture 3', solve('/requests/' + str(N) + '/2', ['https://a/x', 'https://b/file'], ['GET', 'GET'], {}, True, False, False, 'https://start/a', [True, True]), {'request': '/requests/' + str(N) + '/2', 'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'requested': 'https://a/x', 'committed': None}]})
check('fixture 4', solve('/requests/' + str(N) + '/3', ['https://a/x', 'https://b/y'], ['POST', 'POST'], {'form': 'a'}, False, False, True, 'https://start/b', [False, True]), {'request': '/requests/' + str(N) + '/3', 'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'requested': 'https://a/x', 'committed': 'https://b/y'}]})
check('fixture 5', solve('/requests/' + str(N) + '/4', ['https://a/x', 'https://a/y'], ['GET', 'HEAD'], {}, False, True, False, 'https://start/c', [True, True]), {'request': '/requests/' + str(N) + '/4', 'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'requested': 'https://a/x', 'committed': 'https://a/y'}]})
check('fixture 6', solve('/requests/' + str(N) + '/5', ['https://a/x', 'https://b/file'], ['POST', 'GET'], {'download': 'd'}, True, True, True, 'https://start/d', [True, False]), {'request': '/requests/' + str(N) + '/5', 'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'requested': 'https://a/x', 'committed': 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 fixtureActualExpectedOutcome
fixture 1{'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'committed': 'https://c/z', 'requested': 'https://a/x'}], 'request': '/requests/1/0'}{'decision': [['https://c/z'], False, {'view': 'v'}, 1, False, 'https://start/home', ['https://b/y'], 'c', 'document', {'committed': 'https://c/z', 'requested': 'https://a/x'}], 'request': '/requests/1/0'}Passed
fixture 2{'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/1'}{'decision': [['https://a/x'], False, {'view': 'q'}, 1, True, 'https://start/home', [], 'a', 'document', {'committed': 'https://a/x', 'requested': 'https://a/x'}], 'request': '/requests/1/1'}Passed
fixture 3{'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/2'}{'decision': [[], False, {}, 0, False, 'https://start/a', [], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/2'}Passed
fixture 4{'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'committed': 'https://b/y', 'requested': 'https://a/x'}], 'request': '/requests/1/3'}{'decision': [['https://b/y'], True, {'form': 'a'}, 0, True, 'https://start/b', ['https://a/x'], 'b', 'document', {'committed': 'https://b/y', 'requested': 'https://a/x'}], 'request': '/requests/1/3'}Passed
fixture 5{'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'committed': 'https://a/y', 'requested': 'https://a/x'}], 'request': '/requests/1/4'}{'decision': [['https://a/y'], False, {}, 1, False, 'https://start/c', [], 'a', 'document', {'committed': 'https://a/y', 'requested': 'https://a/x'}], 'request': '/requests/1/4'}Passed
fixture 6{'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/5'}{'decision': [[], False, {'download': 'd'}, 1, True, 'https://start/d', ['https://b/file'], 'b', 'download', {'committed': None, 'requested': 'https://a/x'}], 'request': '/requests/1/5'}Passed

SHA-256 / 20ca53c3f235ee6125f87593485f4661877554cd41c572d2664ffdd2a453d6f5

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 2026-09-29T14:41:37.049365+00:00.

Case digest / a51a5a5baec167caaaa38d8760f8e469d8c0822249943d3666f95ca2ff382125