{"abstract":"Range stream idle deadlines advance only on actual byte progress.","category":"HTTP ranges","checks":6,"contract":"Return next idle deadline; positive delivered resets progress to now, zero-byte activity retains last. All integers nonnegative.","evaluation_group":"s3-http_ranges-stream-transfer","failed_approach":"The partial repair uses return last+timeout, which still violates the stated contract.","family":"s3-http_ranges-stream-timeout-last-progress","id":"FA-26621","implementations":{"attempt":{"sha256":"50eed375f718535e7b74ded7e3b4126ae2be13000bef92c083206a523ca2cbb2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(last, now, delivered, timeout):\n    return last+timeout\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-timeout-last-progress fixture 0', solve(N,3*N,0,N), 2*N)\ncheck('stream-timeout-last-progress fixture 1', solve(N,3*N,N,N), 4*N)\ncheck('stream-timeout-last-progress fixture 2', solve(0,0,0,N), N)\ncheck('stream-timeout-last-progress fixture 3', solve(0,N,1,0), N)\ncheck('stream-timeout-last-progress fixture 4', solve(N,N,0,N), 2*N)\ncheck('stream-timeout-last-progress fixture 5', solve(0,N,0,0), 0)\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":"41ea829187437c11bfc9f43fd43323d0edf0ea849f314c471570207fa7dc87dd","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(last, now, delivered, timeout):\n    return now+timeout\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-timeout-last-progress fixture 0', solve(N,3*N,0,N), 2*N)\ncheck('stream-timeout-last-progress fixture 1', solve(N,3*N,N,N), 4*N)\ncheck('stream-timeout-last-progress fixture 2', solve(0,0,0,N), N)\ncheck('stream-timeout-last-progress fixture 3', solve(0,N,1,0), N)\ncheck('stream-timeout-last-progress fixture 4', solve(N,N,0,N), 2*N)\ncheck('stream-timeout-last-progress fixture 5', solve(0,N,0,0), 0)\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"},"fixed":{"sha256":"a17048bb3235c1fc68305b8ff902b0468b668afdab90a43a42b10985a4e4c457","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(last, now, delivered, timeout):\n    return (now if delivered>0 else last)+timeout\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-timeout-last-progress fixture 0', solve(N,3*N,0,N), 2*N)\ncheck('stream-timeout-last-progress fixture 1', solve(N,3*N,N,N), 4*N)\ncheck('stream-timeout-last-progress fixture 2', solve(0,0,0,N), N)\ncheck('stream-timeout-last-progress fixture 3', solve(0,N,1,0), N)\ncheck('stream-timeout-last-progress fixture 4', solve(N,N,0,N), 2*N)\ncheck('stream-timeout-last-progress fixture 5', solve(0,N,0,0), 0)\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-timeout-last-progress","generated_at":"2026-09-29T14:41:17.575351+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.","repair":"Apply the bounded decision exactly: return (now if delivered>0 else last)+timeout","root_cause":"The stream-timeout-last-progress decision uses return now+timeout.","sha256":"17647e780e03ad090e4ef9874c4b679a841627a69f5e058966d5ce06a2deb884","title":"Range stream idle deadlines advance only on actual byte progress · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":46.539,"exit_code":1,"observations":[{"actual":2,"check":"stream-timeout-last-progress fixture 0","expected":2,"passed":true},{"actual":2,"check":"stream-timeout-last-progress fixture 1","expected":4,"passed":false},{"actual":1,"check":"stream-timeout-last-progress fixture 2","expected":1,"passed":true},{"actual":0,"check":"stream-timeout-last-progress fixture 3","expected":1,"passed":false},{"actual":2,"check":"stream-timeout-last-progress fixture 4","expected":2,"passed":true},{"actual":0,"check":"stream-timeout-last-progress fixture 5","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-timeout-last-progress fixture 0\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 1\", \"actual\": 2, \"expected\": 4, \"passed\": false}, {\"check\": \"stream-timeout-last-progress fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 3\", \"actual\": 0, \"expected\": 1, \"passed\": false}, {\"check\": \"stream-timeout-last-progress fixture 4\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 5\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.356,"exit_code":1,"observations":[{"actual":4,"check":"stream-timeout-last-progress fixture 0","expected":2,"passed":false},{"actual":4,"check":"stream-timeout-last-progress fixture 1","expected":4,"passed":true},{"actual":1,"check":"stream-timeout-last-progress fixture 2","expected":1,"passed":true},{"actual":1,"check":"stream-timeout-last-progress fixture 3","expected":1,"passed":true},{"actual":2,"check":"stream-timeout-last-progress fixture 4","expected":2,"passed":true},{"actual":1,"check":"stream-timeout-last-progress fixture 5","expected":0,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-timeout-last-progress fixture 0\", \"actual\": 4, \"expected\": 2, \"passed\": false}, {\"check\": \"stream-timeout-last-progress fixture 1\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 3\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 4\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 5\", \"actual\": 1, \"expected\": 0, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.029,"exit_code":0,"observations":[{"actual":2,"check":"stream-timeout-last-progress fixture 0","expected":2,"passed":true},{"actual":4,"check":"stream-timeout-last-progress fixture 1","expected":4,"passed":true},{"actual":1,"check":"stream-timeout-last-progress fixture 2","expected":1,"passed":true},{"actual":1,"check":"stream-timeout-last-progress fixture 3","expected":1,"passed":true},{"actual":2,"check":"stream-timeout-last-progress fixture 4","expected":2,"passed":true},{"actual":0,"check":"stream-timeout-last-progress fixture 5","expected":0,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-timeout-last-progress fixture 0\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 1\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 2\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 3\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 4\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"stream-timeout-last-progress fixture 5\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}