FA-7006 / Proxy forwarding / Open access
Multiple set cookie fields are not comma coalesced · case 01
Multiple set cookie fields are not comma coalesced.
ROOT CAUSE
The faulty implementation uses `[", ".join(fields)] if fields else []` for the multiple-set-cookie-fields-are-not-comma-coalesced decision.
VERIFIED REPAIR
Apply the explicit multiple-set-cookie-fields-are-not-comma-coalesced contract, including the tested boundary and negative cases.
Unsuccessful approach: The attempted repair uses `list(dict.fromkeys(fields))` and still violates a separate fixture.
Case contract
Bounded offline decision model: multiple set cookie fields are not comma coalesced. Inputs are already validated protocol fields; the explicit fixtures define the supported policy, not a complete protocol implementation.
Why this case matters
This deterministic proxy forwarding model isolates the multiple-set-cookie-fields-are-not-comma-coalesced 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(fields):
return [", ".join(fields)] if fields else []
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['a=1', 'b=2']), ['a=1', 'b=2'])", "check('fixture 2', solve(['a=1', 'a=1']), ['a=1', 'a=1'])", "check('fixture 3', solve([]), [])", "check('fixture 4', solve(['a=1']), ['a=1'])"]
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 | ['a=1, a=1'] | ['a=1', 'a=1'] | Failed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | ['a=1'] | ['a=1'] | Passed |
| fixture 1 | ['a=1, b=2'] | ['a=1', 'b=2'] | Failed |
SHA-256 / ac9be494a5453f816ddcab0eb4c9b2c39a2d617bc34ffbafa5307adb00d9cf30
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(fields):
return list(dict.fromkeys(fields))
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['a=1', 'b=2']), ['a=1', 'b=2'])", "check('fixture 2', solve(['a=1', 'a=1']), ['a=1', 'a=1'])", "check('fixture 3', solve([]), [])", "check('fixture 4', solve(['a=1']), ['a=1'])"]
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 | ['a=1'] | ['a=1', 'a=1'] | Failed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | ['a=1'] | ['a=1'] | Passed |
| fixture 1 | ['a=1', 'b=2'] | ['a=1', 'b=2'] | Passed |
SHA-256 / 402532726870dc15fa8c71448b91ac856a18d86dd1862754d979d5a78409a68a
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(fields):
return list(fields)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve(['a=1', 'b=2']), ['a=1', 'b=2'])", "check('fixture 2', solve(['a=1', 'a=1']), ['a=1', 'a=1'])", "check('fixture 3', solve([]), [])", "check('fixture 4', solve(['a=1']), ['a=1'])"]
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 | ['a=1', 'a=1'] | ['a=1', 'a=1'] | Passed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | ['a=1'] | ['a=1'] | Passed |
| fixture 1 | ['a=1', 'b=2'] | ['a=1', 'b=2'] | Passed |
SHA-256 / 3dafcd92289588491cbcd274c68d5f7693e0ea52cb748f53357f685a3b414685
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 2026-09-29T14:38:07.423182+00:00.
Case digest / 44eb19479cbc5eba6376b27591b591a1e5039cd760cac9b53b2eee0e6e35468b