FA-7606 / WebSocket and browser transport policies / Open access

Websocket control frames do not close fragmented message state · case 01

Websocket control frames do not close fragmented message state.

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

ROOT CAUSE

The faulty implementation uses `not final` for the websocket-control-frames-do-not-close-fragmented-message-state decision.

VERIFIED REPAIR

Apply the explicit websocket-control-frames-do-not-close-fragmented-message-state contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `fragmented or not final` and still violates a separate fixture.

Case contract

Bounded offline decision model: websocket control frames do not close fragmented message state. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.

Why this case matters

This deterministic websocket and browser transport policies model isolates the websocket-control-frames-do-not-close-fragmented-message-state 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(fragmented, opcode, final):
    return not final
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(True, 9, True), True)", "check('fixture 2', solve(True, 0, True), False)", "check('fixture 3', solve(False, 1, False), True)", "check('fixture 4', solve(False, 9, True), False)"]
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	`True`	`True`	Passed
fixture 4	`False`	`False`	Passed
fixture 1	`False`	`True`	Failed

SHA-256 / f26ed643fb483b5c9f24a0e3c9916876b4ab7624d9512993ba56b01565482467

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(fragmented, opcode, final):
    return fragmented or not final
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(True, 9, True), True)", "check('fixture 2', solve(True, 0, True), False)", "check('fixture 3', solve(False, 1, False), True)", "check('fixture 4', solve(False, 9, True), False)"]
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	`True`	`True`	Passed
fixture 4	`False`	`False`	Passed
fixture 1	`True`	`True`	Passed

SHA-256 / e79ccc022d89dd1aa7ee85dd00394ae41709887c19e4fb0f3f0cd55c61051327

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(fragmented, opcode, final):
    return fragmented if opcode >= 8 else not final
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(True, 9, True), True)", "check('fixture 2', solve(True, 0, True), False)", "check('fixture 3', solve(False, 1, False), True)", "check('fixture 4', solve(False, 9, True), False)"]
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	`True`	`True`	Passed
fixture 4	`False`	`False`	Passed
fixture 1	`True`	`True`	Passed

SHA-256 / d4c1816965bc3d46d88d670d3f1088587d4d2988250383bafdc9575b56f1a715

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 2026-09-29T14:38:13.588446+00:00.

Case digest / c9afaeaa3e57a325582b8b3bea13aa34213aa292ca49934028ef3ae6099531ca