{"abstract":"Integrity trailers are emitted only after all promised bytes arrive.","category":"HTTP ranges","checks":6,"contract":"Return digest only after nonaborted completion, None while incomplete or aborted.","evaluation_group":"s3-http_ranges-stream-transfer","failed_approach":"The partial repair uses return digest if remaining==0 else None, which still violates the stated contract.","family":"s3-http_ranges-stream-trailer-after-completion","id":"FA-26591","implementations":{"attempt":{"sha256":"f22b5b77460e8c2cae97a106262025ac5e0654666adc6ac4201bd45bebd66e92","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(remaining, aborted, digest):\n    return digest if remaining==0 else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-trailer-after-completion fixture 0', solve(N,False,\"d\"+str(N)), None)\ncheck('stream-trailer-after-completion fixture 1', solve(0,True,\"d\"), None)\ncheck('stream-trailer-after-completion fixture 2', solve(0,False,\"d\"+str(N)), \"d\"+str(N))\ncheck('stream-trailer-after-completion fixture 3', solve(N,True,\"d\"), None)\ncheck('stream-trailer-after-completion fixture 4', solve(0,False,\"\"), \"\")\ncheck('stream-trailer-after-completion fixture 5', solve(0,True,\"\"), None)\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":"870addc418bc277bf976425eebedcaa603a64a62e2936d818c950beda1a5f318","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(remaining, aborted, digest):\n    return digest\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-trailer-after-completion fixture 0', solve(N,False,\"d\"+str(N)), None)\ncheck('stream-trailer-after-completion fixture 1', solve(0,True,\"d\"), None)\ncheck('stream-trailer-after-completion fixture 2', solve(0,False,\"d\"+str(N)), \"d\"+str(N))\ncheck('stream-trailer-after-completion fixture 3', solve(N,True,\"d\"), None)\ncheck('stream-trailer-after-completion fixture 4', solve(0,False,\"\"), \"\")\ncheck('stream-trailer-after-completion fixture 5', solve(0,True,\"\"), None)\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":"54365ecde61738dff5ddca6ddd5dda60ddfb9a6d30d8f810067afbd98d370c13","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(remaining, aborted, digest):\n    return digest if remaining==0 and not aborted else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-trailer-after-completion fixture 0', solve(N,False,\"d\"+str(N)), None)\ncheck('stream-trailer-after-completion fixture 1', solve(0,True,\"d\"), None)\ncheck('stream-trailer-after-completion fixture 2', solve(0,False,\"d\"+str(N)), \"d\"+str(N))\ncheck('stream-trailer-after-completion fixture 3', solve(N,True,\"d\"), None)\ncheck('stream-trailer-after-completion fixture 4', solve(0,False,\"\"), \"\")\ncheck('stream-trailer-after-completion fixture 5', solve(0,True,\"\"), None)\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-trailer-after-completion","generated_at":"2026-09-29T14:41:17.444662+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 digest if remaining==0 and not aborted else None","root_cause":"The stream-trailer-after-completion decision uses return digest.","sha256":"eab8a272b3f68075e2ff0247c8379aa76ec1c203064a606f88bd13a0825143a8","title":"Integrity trailers are emitted only after all promised bytes arrive · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.341,"exit_code":1,"observations":[{"actual":null,"check":"stream-trailer-after-completion fixture 0","expected":null,"passed":true},{"actual":"d","check":"stream-trailer-after-completion fixture 1","expected":null,"passed":false},{"actual":"d1","check":"stream-trailer-after-completion fixture 2","expected":"d1","passed":true},{"actual":null,"check":"stream-trailer-after-completion fixture 3","expected":null,"passed":true},{"actual":"","check":"stream-trailer-after-completion fixture 4","expected":"","passed":true},{"actual":"","check":"stream-trailer-after-completion fixture 5","expected":null,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-trailer-after-completion fixture 0\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 1\", \"actual\": \"d\", \"expected\": null, \"passed\": false}, {\"check\": \"stream-trailer-after-completion fixture 2\", \"actual\": \"d1\", \"expected\": \"d1\", \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 4\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 5\", \"actual\": \"\", \"expected\": null, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.429,"exit_code":1,"observations":[{"actual":"d1","check":"stream-trailer-after-completion fixture 0","expected":null,"passed":false},{"actual":"d","check":"stream-trailer-after-completion fixture 1","expected":null,"passed":false},{"actual":"d1","check":"stream-trailer-after-completion fixture 2","expected":"d1","passed":true},{"actual":"d","check":"stream-trailer-after-completion fixture 3","expected":null,"passed":false},{"actual":"","check":"stream-trailer-after-completion fixture 4","expected":"","passed":true},{"actual":"","check":"stream-trailer-after-completion fixture 5","expected":null,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-trailer-after-completion fixture 0\", \"actual\": \"d1\", \"expected\": null, \"passed\": false}, {\"check\": \"stream-trailer-after-completion fixture 1\", \"actual\": \"d\", \"expected\": null, \"passed\": false}, {\"check\": \"stream-trailer-after-completion fixture 2\", \"actual\": \"d1\", \"expected\": \"d1\", \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 3\", \"actual\": \"d\", \"expected\": null, \"passed\": false}, {\"check\": \"stream-trailer-after-completion fixture 4\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 5\", \"actual\": \"\", \"expected\": null, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":45.21,"exit_code":0,"observations":[{"actual":null,"check":"stream-trailer-after-completion fixture 0","expected":null,"passed":true},{"actual":null,"check":"stream-trailer-after-completion fixture 1","expected":null,"passed":true},{"actual":"d1","check":"stream-trailer-after-completion fixture 2","expected":"d1","passed":true},{"actual":null,"check":"stream-trailer-after-completion fixture 3","expected":null,"passed":true},{"actual":"","check":"stream-trailer-after-completion fixture 4","expected":"","passed":true},{"actual":null,"check":"stream-trailer-after-completion fixture 5","expected":null,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-trailer-after-completion fixture 0\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 1\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 2\", \"actual\": \"d1\", \"expected\": \"d1\", \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 4\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"stream-trailer-after-completion fixture 5\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}