FA-26451 / HTTP ranges / Open access

Part payloads always precede a framing CRLF · case 01

Part payloads always precede a framing CRLF.

Verified by executionVariant 1 · 6 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The multipart-payload-separator decision uses return body if body.endswith("\r\n") else body+"\r\n".

THE FAILURE

The multipart-payload-separator decision uses return body if body.endswith("\r\n") else body+"\r\n".

Unsuccessful approach: The partial repair uses return body.rstrip("\r\n")+"\r\n", which still violates the stated contract.

Case contract

Append one CRLF framing separator regardless of whether payload already ends in CRLF. The payload itself must remain intact.

Why this case matters

Range responses combine representation identity, conditional requests, framing, and partial-object state.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(body):
    return body if body.endswith("\r\n") else body+"\r\n"
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('multipart-payload-separator fixture 0', solve("x"*N+"\r\n"), "x"*N+"\r\n\r\n")
check('multipart-payload-separator fixture 1', solve(""), "\r\n")
check('multipart-payload-separator fixture 2', solve("x"*N), "x"*N+"\r\n")
check('multipart-payload-separator fixture 3', solve("\r\n\r\n"), "\r\n\r\n\r\n")
check('multipart-payload-separator fixture 4', solve("x\r"), "x\r\r\n")
check('multipart-payload-separator fixture 5', solve("x\n"), "x\n\r\n")
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
multipart-payload-separator fixture 0	`x`	`x`	Failed
multipart-payload-separator fixture 1			Passed
multipart-payload-separator fixture 2	`x`	`x`	Passed
multipart-payload-separator fixture 3			Failed
multipart-payload-separator fixture 4	`x`	`x`	Passed
multipart-payload-separator fixture 5	`x`	`x`	Passed

SHA-256 / 98a63c65ee65487ea9dd6fa003d2e677283ee7a06d516b4979a8d6aebaf67f57

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(body):
    return body.rstrip("\r\n")+"\r\n"
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('multipart-payload-separator fixture 0', solve("x"*N+"\r\n"), "x"*N+"\r\n\r\n")
check('multipart-payload-separator fixture 1', solve(""), "\r\n")
check('multipart-payload-separator fixture 2', solve("x"*N), "x"*N+"\r\n")
check('multipart-payload-separator fixture 3', solve("\r\n\r\n"), "\r\n\r\n\r\n")
check('multipart-payload-separator fixture 4', solve("x\r"), "x\r\r\n")
check('multipart-payload-separator fixture 5', solve("x\n"), "x\n\r\n")
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
multipart-payload-separator fixture 0	`x`	`x`	Failed
multipart-payload-separator fixture 1			Passed
multipart-payload-separator fixture 2	`x`	`x`	Passed
multipart-payload-separator fixture 3			Failed
multipart-payload-separator fixture 4	`x`	`x`	Failed
multipart-payload-separator fixture 5	`x`	`x`	Failed

SHA-256 / aa31114512d1519671f34b12c3b1b4a13b155df3e0aefe96e01b034696ccdab6

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 6 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

Deterministic simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. 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 2026-09-29T14:41:16.210764+00:00.

Case digest / 87588448e927f731d3bd929e4aabff9b363eede880316d3173abaeae7ea3861d