FA-6881 / Content negotiation / Open access
Content length after coding describes transmitted octets · case 01
Content length after coding describes transmitted octets.
ROOT CAUSE
The faulty implementation uses `len(plain)` for the content-length-after-coding-describes-transmitted-octets decision.
VERIFIED REPAIR
Apply the explicit content-length-after-coding-describes-transmitted-octets contract, including the tested boundary and negative cases.
Unsuccessful approach: The attempted repair uses `sum(len(chunk) for chunk in coded) if coded else len(plain.encode("utf-8"))` and still violates a separate fixture.
Case contract
Given plain, coded, content length after coding describes transmitted octets. Return the protocol decision or transformed value; fields are validated and fixtures state boundary outcomes.
Why this case matters
This deterministic content negotiation model isolates the content-length-after-coding-describes-transmitted-octets 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(plain, coded):
return len(plain)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('é', None), 2)", "check('fixture 2', solve('hello', ['a', 'bc']), 3)", "check('fixture 3', solve('hello', []), 0)", "check('fixture 4', solve('', None), 0)"]
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 | 5 | 3 | Failed |
| fixture 3 | 5 | 0 | Failed |
| fixture 4 | 0 | 0 | Passed |
| fixture 1 | 1 | 2 | Failed |
SHA-256 / 129f027c670a0bb437cd909e093bd1dc07011b190886033171c6b6533e215cfb
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(plain, coded):
return sum(len(chunk) for chunk in coded) if coded else len(plain.encode("utf-8"))
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('é', None), 2)", "check('fixture 2', solve('hello', ['a', 'bc']), 3)", "check('fixture 3', solve('hello', []), 0)", "check('fixture 4', solve('', None), 0)"]
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 | 3 | 3 | Passed |
| fixture 3 | 5 | 0 | Failed |
| fixture 4 | 0 | 0 | Passed |
| fixture 1 | 2 | 2 | Passed |
SHA-256 / 0a4fccc41f0a3470788635f1322c5ed553982afe43bca76975646edfe444fc63
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(plain, coded):
return sum(len(chunk) for chunk in coded) if coded is not None else len(plain.encode("utf-8"))
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
_fixtures = ["check('fixture 1', solve('é', None), 2)", "check('fixture 2', solve('hello', ['a', 'bc']), 3)", "check('fixture 3', solve('hello', []), 0)", "check('fixture 4', solve('', None), 0)"]
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 | 3 | 3 | Passed |
| fixture 3 | 0 | 0 | Passed |
| fixture 4 | 0 | 0 | Passed |
| fixture 1 | 2 | 2 | Passed |
SHA-256 / 72e57906641b072673221e2b07e0b200a600f51a76c6e7c0470a71ad3e0a999a
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 2026-09-29T14:38:06.184126+00:00.
Case digest / 4cc15663b80b50dfa977cff482a890272d0fcdb9fd1c6be7d967cace9465ab1c