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FA-28176 / HTTP redirects / Open access

Release an intermediate response before following its target: discard byte accounting · case 01

Release an intermediate response before following its target: the discard byte accounting branch emits an incorrect decision.

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

ROOT CAUSE

The discard-byte-accounting decision uses '0'; this violates the stipulated controller policy.

THE FAILURE

The discard-byte-accounting decision uses '0'; this violates the stipulated controller policy.

Unsuccessful approach: The partial repair uses 'remaining+1' and still fails an explicit boundary or control.

Case contract

Release an intermediate response before following its target. 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, drained, remaining, reusable, closed, canceled, http2):
    return {'request': request, 'decision': [not drained and remaining > 0, reusable and drained and not closed, not http2 and remaining > 0 and not reusable, http2 and remaining > 0, not canceled and not closed, 'eof' if remaining == 0 else 'pending', not closed, 0, 'stream' if http2 else 'connection', 'released' if closed else ('canceling' if canceled else 'owned')]} 
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', False, 8, True, False, False, False), {'request': '/requests/' + str(N) + '/0', 'decision': [True, False, False, False, True, 'pending', True, 8, 'connection', 'owned']})
check('fixture 2', solve('/requests/' + str(N) + '/1', True, 0, True, False, False, False), {'request': '/requests/' + str(N) + '/1', 'decision': [False, True, False, False, True, 'eof', True, 0, 'connection', 'owned']})
check('fixture 3', solve('/requests/' + str(N) + '/2', False, 3, False, False, False, False), {'request': '/requests/' + str(N) + '/2', 'decision': [True, False, True, False, True, 'pending', True, 3, 'connection', 'owned']})
check('fixture 4', solve('/requests/' + str(N) + '/3', False, 5, True, False, True, True), {'request': '/requests/' + str(N) + '/3', 'decision': [True, False, False, True, False, 'pending', True, 5, 'stream', 'canceling']})
check('fixture 5', solve('/requests/' + str(N) + '/4', True, 0, True, True, False, True), {'request': '/requests/' + str(N) + '/4', 'decision': [False, False, False, False, False, 'eof', False, 0, 'stream', 'released']})
check('fixture 6', solve('/requests/' + str(N) + '/5', False, 0, False, True, True, False), {'request': '/requests/' + str(N) + '/5', 'decision': [False, False, False, False, False, 'eof', False, 0, 'connection', 'released']})
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': [True, False, False, False, True, 'pending', True, 0, 'connection', 'owned'], 'request': '/requests/1/0'}{'decision': [True, False, False, False, True, 'pending', True, 8, 'connection', 'owned'], 'request': '/requests/1/0'}Failed
fixture 2{'decision': [False, True, False, False, True, 'eof', True, 0, 'connection', 'owned'], 'request': '/requests/1/1'}{'decision': [False, True, False, False, True, 'eof', True, 0, 'connection', 'owned'], 'request': '/requests/1/1'}Passed
fixture 3{'decision': [True, False, True, False, True, 'pending', True, 0, 'connection', 'owned'], 'request': '/requests/1/2'}{'decision': [True, False, True, False, True, 'pending', True, 3, 'connection', 'owned'], 'request': '/requests/1/2'}Failed
fixture 4{'decision': [True, False, False, True, False, 'pending', True, 0, 'stream', 'canceling'], 'request': '/requests/1/3'}{'decision': [True, False, False, True, False, 'pending', True, 5, 'stream', 'canceling'], 'request': '/requests/1/3'}Failed
fixture 5{'decision': [False, False, False, False, False, 'eof', False, 0, 'stream', 'released'], 'request': '/requests/1/4'}{'decision': [False, False, False, False, False, 'eof', False, 0, 'stream', 'released'], 'request': '/requests/1/4'}Passed
fixture 6{'decision': [False, False, False, False, False, 'eof', False, 0, 'connection', 'released'], 'request': '/requests/1/5'}{'decision': [False, False, False, False, False, 'eof', False, 0, 'connection', 'released'], 'request': '/requests/1/5'}Passed

SHA-256 / e3399cd33a9fa532d31e7233c8e05d07dde08a03a26e1db5fa9d62d2a6c63f24

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, drained, remaining, reusable, closed, canceled, http2):
    return {'request': request, 'decision': [not drained and remaining > 0, reusable and drained and not closed, not http2 and remaining > 0 and not reusable, http2 and remaining > 0, not canceled and not closed, 'eof' if remaining == 0 else 'pending', not closed, remaining+1, 'stream' if http2 else 'connection', 'released' if closed else ('canceling' if canceled else 'owned')]} 
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1', solve('/requests/' + str(N) + '/0', False, 8, True, False, False, False), {'request': '/requests/' + str(N) + '/0', 'decision': [True, False, False, False, True, 'pending', True, 8, 'connection', 'owned']})
check('fixture 2', solve('/requests/' + str(N) + '/1', True, 0, True, False, False, False), {'request': '/requests/' + str(N) + '/1', 'decision': [False, True, False, False, True, 'eof', True, 0, 'connection', 'owned']})
check('fixture 3', solve('/requests/' + str(N) + '/2', False, 3, False, False, False, False), {'request': '/requests/' + str(N) + '/2', 'decision': [True, False, True, False, True, 'pending', True, 3, 'connection', 'owned']})
check('fixture 4', solve('/requests/' + str(N) + '/3', False, 5, True, False, True, True), {'request': '/requests/' + str(N) + '/3', 'decision': [True, False, False, True, False, 'pending', True, 5, 'stream', 'canceling']})
check('fixture 5', solve('/requests/' + str(N) + '/4', True, 0, True, True, False, True), {'request': '/requests/' + str(N) + '/4', 'decision': [False, False, False, False, False, 'eof', False, 0, 'stream', 'released']})
check('fixture 6', solve('/requests/' + str(N) + '/5', False, 0, False, True, True, False), {'request': '/requests/' + str(N) + '/5', 'decision': [False, False, False, False, False, 'eof', False, 0, 'connection', 'released']})
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': [True, False, False, False, True, 'pending', True, 9, 'connection', 'owned'], 'request': '/requests/1/0'}{'decision': [True, False, False, False, True, 'pending', True, 8, 'connection', 'owned'], 'request': '/requests/1/0'}Failed
fixture 2{'decision': [False, True, False, False, True, 'eof', True, 1, 'connection', 'owned'], 'request': '/requests/1/1'}{'decision': [False, True, False, False, True, 'eof', True, 0, 'connection', 'owned'], 'request': '/requests/1/1'}Failed
fixture 3{'decision': [True, False, True, False, True, 'pending', True, 4, 'connection', 'owned'], 'request': '/requests/1/2'}{'decision': [True, False, True, False, True, 'pending', True, 3, 'connection', 'owned'], 'request': '/requests/1/2'}Failed
fixture 4{'decision': [True, False, False, True, False, 'pending', True, 6, 'stream', 'canceling'], 'request': '/requests/1/3'}{'decision': [True, False, False, True, False, 'pending', True, 5, 'stream', 'canceling'], 'request': '/requests/1/3'}Failed
fixture 5{'decision': [False, False, False, False, False, 'eof', False, 1, 'stream', 'released'], 'request': '/requests/1/4'}{'decision': [False, False, False, False, False, 'eof', False, 0, 'stream', 'released'], 'request': '/requests/1/4'}Failed
fixture 6{'decision': [False, False, False, False, False, 'eof', False, 1, 'connection', 'released'], 'request': '/requests/1/5'}{'decision': [False, False, False, False, False, 'eof', False, 0, 'connection', 'released'], 'request': '/requests/1/5'}Failed

SHA-256 / 1050c3f4cc23f201972ff52df80fdf7cd7e5ec07a631a5b9ad32b844cb983c06

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 6 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.

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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 2026-09-29T14:41:31.704492+00:00.

Case digest / d9477c433a634255f402a097dbc127ab3331254b0b1719e0db78aed53713e0c4