FA-26656 / HTTP ranges / Open access

A range member has exactly one separator dash · case 01

A range member has exactly one separator dash.

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

ROOT CAUSE

The range-member-dash-count decision uses p=member.split("-") return p[:2] if len(p)>=2 else None.

THE FAILURE

The range-member-dash-count decision uses p=member.split("-") return p[:2] if len(p)>=2 else None.

Unsuccessful approach: The partial repair uses p=member.split("-",1) return p if len(p)==2 else None, which still violates the stated contract.

Case contract

Return the two text components for exactly one dash, allowing empty one-sided forms but rejecting both empty. Otherwise None.

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(member):
    p=member.split("-")
    return p[:2] if len(p)>=2 else None
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('range-member-dash-count fixture 0', solve("0-1-"+str(N)), None)
check('range-member-dash-count fixture 1', solve("-"), None)
check('range-member-dash-count fixture 2', solve("0-"+str(N)), ["0",str(N)])
check('range-member-dash-count fixture 3', solve("-"+str(N)), ["",str(N)])
check('range-member-dash-count fixture 4', solve(str(N)+"-"), [str(N),""])
check('range-member-dash-count fixture 5', solve(str(N)), None)
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
range-member-dash-count fixture 0	`['0', '1']`	`None`	Failed
range-member-dash-count fixture 1	`['', '']`	`None`	Failed
range-member-dash-count fixture 2	`['0', '1']`	`['0', '1']`	Passed
range-member-dash-count fixture 3	`['', '1']`	`['', '1']`	Passed
range-member-dash-count fixture 4	`['1', '']`	`['1', '']`	Passed
range-member-dash-count fixture 5	`None`	`None`	Passed

SHA-256 / dc98404804f92b2243023b83bc5df1283267f3fcb983e4a8f40ab91ab1421eed

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(member):
    p=member.split("-",1)
    return p if len(p)==2 else None
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('range-member-dash-count fixture 0', solve("0-1-"+str(N)), None)
check('range-member-dash-count fixture 1', solve("-"), None)
check('range-member-dash-count fixture 2', solve("0-"+str(N)), ["0",str(N)])
check('range-member-dash-count fixture 3', solve("-"+str(N)), ["",str(N)])
check('range-member-dash-count fixture 4', solve(str(N)+"-"), [str(N),""])
check('range-member-dash-count fixture 5', solve(str(N)), None)
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
range-member-dash-count fixture 0	`['0', '1-1']`	`None`	Failed
range-member-dash-count fixture 1	`['', '']`	`None`	Failed
range-member-dash-count fixture 2	`['0', '1']`	`['0', '1']`	Passed
range-member-dash-count fixture 3	`['', '1']`	`['', '1']`	Passed
range-member-dash-count fixture 4	`['1', '']`	`['1', '']`	Passed
range-member-dash-count fixture 5	`None`	`None`	Passed

SHA-256 / 5568c807c11e9de90af13810211b35321cfc7f8e88bc9f8030ef71381ae01d9f

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 2026-09-29T14:41:17.983427+00:00.

Case digest / 8233d286586f5fd7da93c0f38d13b79436dbfaf3186540969be75f92dd50b7c8