FA-7601 / WebSocket and browser transport policies / Open access

Websocket continuation requires an open fragmented message · case 01

Websocket continuation requires an open fragmented message.

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

ROOT CAUSE

The faulty implementation uses `not fragmented if opcode in (1,2) else True` for the websocket-continuation-requires-an-open-fragmented-message decision.

VERIFIED REPAIR

Apply the explicit websocket-continuation-requires-an-open-fragmented-message contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `fragmented if opcode == 0 else not fragmented` and still violates a separate fixture.

Case contract

Bounded offline decision model: websocket continuation requires an open fragmented message. 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-continuation-requires-an-open-fragmented-message 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(opcode, fragmented):
    return not fragmented if opcode in (1,2) else True
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(0, False), False)", "check('fixture 2', solve(1, True), False)", "check('fixture 3', solve(9, True), True)", "check('fixture 4', solve(0, True), 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	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`True`	`False`	Failed

SHA-256 / d71a4db52bd921695f1a821dad407aaa07dc32de96190f2ee397b6028992af28

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

SHA-256 / 29d68708add560b9a068fcbbe88769f54c9da345c7315f82594132889e968acd

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

SHA-256 / 83ab14048b6921925dbd3c860eb590f7e791c26621ad2c1dcf383f2dccf6caaa

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 2026-09-29T14:38:13.556461+00:00.

Case digest / d93e7ba2e7f7ad3562fb5e58d25c3c6636d255ee3c223540301c277b06fb9571