FA-6621 / HTTP semantics / Open access

Unsupported expectations are rejected independently of body length · case 01

Unsupported expectations are rejected independently of body length.

Verified by executionVariant 1 · 4 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The faulty implementation uses `False` for the unknown-expectation decision.

VERIFIED REPAIR

Apply the explicit unknown-expectation contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `bool(tokens)` and still violates a separate fixture.

Case contract

Unsupported expectations are rejected independently of body length: return the result specified by the explicit input/output boundary fixtures.

Why this case matters

This deterministic http semantics model isolates the unknown-expectation policy at a network component boundary.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(tokens):
    return False
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['extension']), True)", "check('fixture 2', solve(['100-continue']), False)", "check('fixture 3', solve([]), False)", "check('fixture 4', solve(['100-continue', 'x']), True)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
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 2	`False`	`False`	Passed
fixture 3	`False`	`False`	Passed
fixture 4	`False`	`True`	Failed
fixture 1	`False`	`True`	Failed

SHA-256 / ce62fa19be4006f43d544c5d88a8ef5096ff752aa727737fc2980c9deeea31b2

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(tokens):
    return bool(tokens)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['extension']), True)", "check('fixture 2', solve(['100-continue']), False)", "check('fixture 3', solve([]), False)", "check('fixture 4', solve(['100-continue', 'x']), True)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
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 2	`True`	`False`	Failed
fixture 3	`False`	`False`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`True`	`True`	Passed

SHA-256 / f0c34d6ed603e83d473c82440c78ddf1cd4273e220d3a870b348a09580289ee6

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import ipaddress
import re
from urllib.parse import urlsplit, urljoin
N = 1
observations = []
def solve(tokens):
    return any(t.lower() != '100-continue' for t in tokens)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['extension']), True)", "check('fixture 2', solve(['100-continue']), False)", "check('fixture 3', solve([]), False)", "check('fixture 4', solve(['100-continue', 'x']), True)"]
for _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:
    exec(_line)
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 2	`False`	`False`	Passed
fixture 3	`False`	`False`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`True`	`True`	Passed

SHA-256 / f9225f758f23fcf725d7d63f255f7a31473a34883ad190ef5438eb160374bc32

Verification & scope

Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. 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 2026-09-29T14:38:03.753858+00:00.

Case digest / 546414455bfca473cd70397f66aff7da1a11e4fecc13eba58dfebb07b55fc4dd