{"abstract":"Download accounting counts accepted payload bytes instead of attempted bytes.","category":"HTTP ranges","checks":6,"contract":"writes are [attempted,accepted] payload counts, 0<=accepted<=attempted. Return delivered count.","contract_signature":"writes","evaluation_group":"s3-http_ranges-stream-transfer","failed_approach":"The partial repair uses return sum(b for a,b in writes if b==a), which still violates the stated contract.","family":"s3-http_ranges-stream-delivery-count-accepted","id":"FA-26611","implementations":{"attempt":{"sha256":"b858fe69f704fe1c5f1be49e6d00cebea5f3a4df84b99915fe39d819ef002c1e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(writes):\n    return sum(b for a,b in writes if b==a)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-delivery-count-accepted fixture 0', solve([[3*N,N]]), N)\ncheck('stream-delivery-count-accepted fixture 1', solve([[N,0],[N,N]]), N)\ncheck('stream-delivery-count-accepted fixture 2', solve([]), 0)\ncheck('stream-delivery-count-accepted fixture 3', solve([[N,N]]), N)\ncheck('stream-delivery-count-accepted fixture 4', solve([[0,0]]), 0)\ncheck('stream-delivery-count-accepted fixture 5', solve([[4*N,N],[2*N,N]]), 2*N)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"8f64c7a1e191026ba44015c40bc16953441ad587f953bc3b23d840f0e64eb321","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(writes):\n    return sum(a for a,b in writes)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-delivery-count-accepted fixture 0', solve([[3*N,N]]), N)\ncheck('stream-delivery-count-accepted fixture 1', solve([[N,0],[N,N]]), N)\ncheck('stream-delivery-count-accepted fixture 2', solve([]), 0)\ncheck('stream-delivery-count-accepted fixture 3', solve([[N,N]]), N)\ncheck('stream-delivery-count-accepted fixture 4', solve([[0,0]]), 0)\ncheck('stream-delivery-count-accepted fixture 5', solve([[4*N,N],[2*N,N]]), 2*N)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"s3-http_ranges-stream-delivery-count-accepted","generated_at":"2026-09-29T14:41:17.535435+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Range responses combine representation identity, conditional requests, framing, and partial-object state.","root_cause":"The stream-delivery-count-accepted decision uses return sum(a for a,b in writes).","sha256":"f18c422aaa89bb247ee6719a6c47d14b5c7047211aab5a081e99f89999276a8c","title":"Download accounting counts accepted payload bytes instead of attempted bytes · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":42.017,"exit_code":1,"observations":[{"actual":0,"check":"stream-delivery-count-accepted fixture 0","expected":1,"passed":false},{"actual":1,"check":"stream-delivery-count-accepted fixture 1","expected":1,"passed":true},{"actual":0,"check":"stream-delivery-count-accepted fixture 2","expected":0,"passed":true},{"actual":1,"check":"stream-delivery-count-accepted fixture 3","expected":1,"passed":true},{"actual":0,"check":"stream-delivery-count-accepted fixture 4","expected":0,"passed":true},{"actual":0,"check":"stream-delivery-count-accepted fixture 5","expected":2,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-delivery-count-accepted fixture 0\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"stream-delivery-count-accepted fixture 1\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-delivery-count-accepted fixture 2\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"stream-delivery-count-accepted fixture 3\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-delivery-count-accepted fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"stream-delivery-count-accepted fixture 5\", \"actual\": 0, \"expected\": 2, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.351,"exit_code":1,"observations":[{"actual":3,"check":"stream-delivery-count-accepted fixture 0","expected":1,"passed":false},{"actual":2,"check":"stream-delivery-count-accepted fixture 1","expected":1,"passed":false},{"actual":0,"check":"stream-delivery-count-accepted fixture 2","expected":0,"passed":true},{"actual":1,"check":"stream-delivery-count-accepted fixture 3","expected":1,"passed":true},{"actual":0,"check":"stream-delivery-count-accepted fixture 4","expected":0,"passed":true},{"actual":6,"check":"stream-delivery-count-accepted fixture 5","expected":2,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-delivery-count-accepted fixture 0\", \"actual\": 3, \"expected\": 1, \"passed\": false}, {\"check\": \"stream-delivery-count-accepted fixture 1\", \"actual\": 2, \"expected\": 1, \"passed\": false}, {\"check\": \"stream-delivery-count-accepted fixture 2\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"stream-delivery-count-accepted fixture 3\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-delivery-count-accepted fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"stream-delivery-count-accepted fixture 5\", \"actual\": 6, \"expected\": 2, \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}