{"abstract":"Missing response validators cannot silently preserve a saved validator.","category":"HTTP ranges","checks":6,"contract":"Resumption accepts only an explicitly present incoming validator equal to the saved strong tag; absent or changed tags yield None.","evaluation_group":"s3-http_ranges-resume-client","failed_approach":"The partial repair uses return body if (incoming or saved)==saved else None, which still violates the stated contract.","family":"s3-http_ranges-resume-etag-must-be-present","id":"FA-26751","implementations":{"attempt":{"sha256":"3917806d407ba648629cc738bf46defaca437d31279881063c779a10435526c6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(saved, incoming, body):\n    return body if (incoming or saved)==saved else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-etag-must-be-present fixture 0', solve(\"v\",None,\"p\"*N), None)\ncheck('resume-etag-must-be-present fixture 1', solve(\"v\",\"\",\"p\"), None)\ncheck('resume-etag-must-be-present fixture 2', solve(\"v\",\"v\",\"p\"*N), \"p\"*N)\ncheck('resume-etag-must-be-present fixture 3', solve(\"v\",\"w\",\"p\"), None)\ncheck('resume-etag-must-be-present fixture 4', solve(\"\", \"\", \"p\"), \"p\")\ncheck('resume-etag-must-be-present fixture 5', solve(\"v\",\"v\",\"\"), \"\")\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":"ce5f69f0db123166ad696143880c140913bde09e72476b180539113f56659368","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(saved, incoming, body):\n    return body if incoming is None or incoming==saved else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-etag-must-be-present fixture 0', solve(\"v\",None,\"p\"*N), None)\ncheck('resume-etag-must-be-present fixture 1', solve(\"v\",\"\",\"p\"), None)\ncheck('resume-etag-must-be-present fixture 2', solve(\"v\",\"v\",\"p\"*N), \"p\"*N)\ncheck('resume-etag-must-be-present fixture 3', solve(\"v\",\"w\",\"p\"), None)\ncheck('resume-etag-must-be-present fixture 4', solve(\"\", \"\", \"p\"), \"p\")\ncheck('resume-etag-must-be-present fixture 5', solve(\"v\",\"v\",\"\"), \"\")\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":"8e9282355c75cee733311fcfd70eef5c40bf5694e60eec706afd16d4e60e406d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(saved, incoming, body):\n    return body if incoming is not None and incoming==saved else None\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('resume-etag-must-be-present fixture 0', solve(\"v\",None,\"p\"*N), None)\ncheck('resume-etag-must-be-present fixture 1', solve(\"v\",\"\",\"p\"), None)\ncheck('resume-etag-must-be-present fixture 2', solve(\"v\",\"v\",\"p\"*N), \"p\"*N)\ncheck('resume-etag-must-be-present fixture 3', solve(\"v\",\"w\",\"p\"), None)\ncheck('resume-etag-must-be-present fixture 4', solve(\"\", \"\", \"p\"), \"p\")\ncheck('resume-etag-must-be-present fixture 5', solve(\"v\",\"v\",\"\"), \"\")\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-resume-etag-must-be-present","generated_at":"2026-09-29T14:41:18.778722+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 body if incoming is not None and incoming==saved else None","root_cause":"The resume-etag-must-be-present decision uses return body if incoming is None or incoming==saved else None.","sha256":"cb734cfd22be0b87bddc3fe52e3de38bd157e8f2913e299f805fe96a2882c01d","title":"Missing response validators cannot silently preserve a saved validator · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.553,"exit_code":1,"observations":[{"actual":"p","check":"resume-etag-must-be-present fixture 0","expected":null,"passed":false},{"actual":"p","check":"resume-etag-must-be-present fixture 1","expected":null,"passed":false},{"actual":"p","check":"resume-etag-must-be-present fixture 2","expected":"p","passed":true},{"actual":null,"check":"resume-etag-must-be-present fixture 3","expected":null,"passed":true},{"actual":"p","check":"resume-etag-must-be-present fixture 4","expected":"p","passed":true},{"actual":"","check":"resume-etag-must-be-present fixture 5","expected":"","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-etag-must-be-present fixture 0\", \"actual\": \"p\", \"expected\": null, \"passed\": false}, {\"check\": \"resume-etag-must-be-present fixture 1\", \"actual\": \"p\", \"expected\": null, \"passed\": false}, {\"check\": \"resume-etag-must-be-present fixture 2\", \"actual\": \"p\", \"expected\": \"p\", \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 4\", \"actual\": \"p\", \"expected\": \"p\", \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 5\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.895,"exit_code":1,"observations":[{"actual":"p","check":"resume-etag-must-be-present fixture 0","expected":null,"passed":false},{"actual":null,"check":"resume-etag-must-be-present fixture 1","expected":null,"passed":true},{"actual":"p","check":"resume-etag-must-be-present fixture 2","expected":"p","passed":true},{"actual":null,"check":"resume-etag-must-be-present fixture 3","expected":null,"passed":true},{"actual":"p","check":"resume-etag-must-be-present fixture 4","expected":"p","passed":true},{"actual":"","check":"resume-etag-must-be-present fixture 5","expected":"","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-etag-must-be-present fixture 0\", \"actual\": \"p\", \"expected\": null, \"passed\": false}, {\"check\": \"resume-etag-must-be-present fixture 1\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 2\", \"actual\": \"p\", \"expected\": \"p\", \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 4\", \"actual\": \"p\", \"expected\": \"p\", \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 5\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.024,"exit_code":0,"observations":[{"actual":null,"check":"resume-etag-must-be-present fixture 0","expected":null,"passed":true},{"actual":null,"check":"resume-etag-must-be-present fixture 1","expected":null,"passed":true},{"actual":"p","check":"resume-etag-must-be-present fixture 2","expected":"p","passed":true},{"actual":null,"check":"resume-etag-must-be-present fixture 3","expected":null,"passed":true},{"actual":"p","check":"resume-etag-must-be-present fixture 4","expected":"p","passed":true},{"actual":"","check":"resume-etag-must-be-present fixture 5","expected":"","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"resume-etag-must-be-present fixture 0\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 1\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 2\", \"actual\": \"p\", \"expected\": \"p\", \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 3\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 4\", \"actual\": \"p\", \"expected\": \"p\", \"passed\": true}, {\"check\": \"resume-etag-must-be-present fixture 5\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}