FA-7461 / Multiplexed protocols / Open access

Http2 server push identifiers are positive even · case 01

Http2 server push identifiers are positive even.

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

ROOT CAUSE

The faulty implementation uses `stream % 2 == 0` for the http2-server-push-identifiers-are-positive-even decision.

VERIFIED REPAIR

Apply the explicit http2-server-push-identifiers-are-positive-even contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `stream >= 0` and still violates a separate fixture.

Case contract

Bounded offline decision model: http2 server push identifiers are positive even. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.

Why this case matters

This deterministic multiplexed protocols model isolates the http2-server-push-identifiers-are-positive-even 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(stream):
    return stream % 2 == 0
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(2), True)", "check('fixture 2', solve(0), False)", "check('fixture 3', solve(1), False)", "check('fixture 4', solve(-2), 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	`False`	`False`	Passed
fixture 4	`True`	`False`	Failed
fixture 1	`True`	`True`	Passed

SHA-256 / 9bac6543ce006600b189b1175b7ec6b1b457c5e980bf811cd2b729ed0be78b19

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(stream):
    return stream >= 0
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(2), True)", "check('fixture 2', solve(0), False)", "check('fixture 3', solve(1), False)", "check('fixture 4', solve(-2), 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`	`False`	Failed
fixture 4	`False`	`False`	Passed
fixture 1	`True`	`True`	Passed

SHA-256 / f5ba92bf1ffc1cdbba97aad2eb3ebe4555141ede06ec5db475427cb1349c8db7

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(stream):
    return stream > 0 and stream % 2 == 0
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(2), True)", "check('fixture 2', solve(0), False)", "check('fixture 3', solve(1), False)", "check('fixture 4', solve(-2), 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	`False`	`False`	Passed
fixture 4	`False`	`False`	Passed
fixture 1	`True`	`True`	Passed

SHA-256 / 604b49710762ab4076372f72c15f26c7de78978b3c189fa93316b0a3e81d0775

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 2026-09-29T14:38:12.276910+00:00.

Case digest / 78e5f6517bb0dcde6626c131382b69b1f69840e02cb4f8fa55ac04888b0d65f1