FA-7521 / Multiplexed protocols / Open access

Http2 field names must be lowercase · case 01

Http2 field names must be lowercase.

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

ROOT CAUSE

The faulty implementation uses `True` for the http2-field-names-must-be-lowercase decision.

VERIFIED REPAIR

Apply the explicit http2-field-names-must-be-lowercase contract, including the tested boundary and negative cases.

Unsuccessful approach: The attempted repair uses `all(n.islower() for n in names)` and still violates a separate fixture.

Case contract

Bounded offline decision model: http2 field names must be lowercase. 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-field-names-must-be-lowercase 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(names):
    return True
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['Content-Type']), False)", "check('fixture 2', solve(['123']), True)", "check('fixture 3', solve(['content-type']), True)", "check('fixture 4', solve([]), 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`	`True`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`True`	`False`	Failed

SHA-256 / 83a2a8b291993f9b6471f73d5086a9b3bd9fdc3ca4e7bafd99cf72ee607a6488

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(names):
    return all(n.islower() for n in names)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['Content-Type']), False)", "check('fixture 2', solve(['123']), True)", "check('fixture 3', solve(['content-type']), True)", "check('fixture 4', solve([]), 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`	`True`	Failed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`False`	`False`	Passed

SHA-256 / 8c0e48afe942536d84b06ede9fd6264c8deed2fd27507fa920a574a9da6295c3

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(names):
    return all(n == n.lower() for n in names)
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['Content-Type']), False)", "check('fixture 2', solve(['123']), True)", "check('fixture 3', solve(['content-type']), True)", "check('fixture 4', solve([]), 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`	`True`	Passed
fixture 3	`True`	`True`	Passed
fixture 4	`True`	`True`	Passed
fixture 1	`False`	`False`	Passed

SHA-256 / c6ff29c7dc32f8f6e4d5ce35b7d097095efcaf1b8eb4d5460103ea54de63bdaa

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 2026-09-29T14:38:12.907860+00:00.

Case digest / 6df81ee44da64da57d6fb59177430dd0a4fa38097861ae8ad4885daa33868bee