{"abstract":"Failed write-independent preconditions precede range parsing.","category":"HTTP ranges","checks":6,"contract":"Return [status,body]: failed If-Match is 412 before examining a malformed range; otherwise malformed range is 400 and valid range 206.","evaluation_group":"s3-http_ranges-conditional","failed_approach":"The partial repair uses return [412, \"\"] if not match_ok and range_valid else ([206,body] if range_valid else [400,\"\"]), which still violates the stated contract.","family":"s3-http_ranges-precondition-before-range","id":"FA-26341","implementations":{"attempt":{"sha256":"3568f196e71ab699764bfee1dcb37390926d74afefffc4c68322874c9b11a9f8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(match_ok, range_valid, body):\n    return [412, \"\"] if not match_ok and range_valid else ([206,body] if range_valid else [400,\"\"])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('precondition-before-range fixture 0', solve(False,False,\"x\"*N), [412,\"\"])\ncheck('precondition-before-range fixture 1', solve(False,True,\"x\"*N), [412,\"\"])\ncheck('precondition-before-range fixture 2', solve(True,False,\"x\"*N), [400,\"\"])\ncheck('precondition-before-range fixture 3', solve(True,True,\"x\"*N), [206,\"x\"*N])\ncheck('precondition-before-range fixture 4', solve(False,False,\"\"), [412,\"\"])\ncheck('precondition-before-range fixture 5', solve(True,True,\"\"), [206,\"\"])\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":"fcc367f9371053c0729bd1c612b55912eea09774fa0b76873b49b181cb8eb301","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(match_ok, range_valid, body):\n    return [400, \"\"] if not range_valid else ([206,body] if match_ok else [412,\"\"])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('precondition-before-range fixture 0', solve(False,False,\"x\"*N), [412,\"\"])\ncheck('precondition-before-range fixture 1', solve(False,True,\"x\"*N), [412,\"\"])\ncheck('precondition-before-range fixture 2', solve(True,False,\"x\"*N), [400,\"\"])\ncheck('precondition-before-range fixture 3', solve(True,True,\"x\"*N), [206,\"x\"*N])\ncheck('precondition-before-range fixture 4', solve(False,False,\"\"), [412,\"\"])\ncheck('precondition-before-range fixture 5', solve(True,True,\"\"), [206,\"\"])\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":"b044c80862b522f38d42b82e129b3729a057716b8aa0fef281e51d95ac80c081","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(match_ok, range_valid, body):\n    return [412, \"\"] if not match_ok else ([206,body] if range_valid else [400,\"\"])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('precondition-before-range fixture 0', solve(False,False,\"x\"*N), [412,\"\"])\ncheck('precondition-before-range fixture 1', solve(False,True,\"x\"*N), [412,\"\"])\ncheck('precondition-before-range fixture 2', solve(True,False,\"x\"*N), [400,\"\"])\ncheck('precondition-before-range fixture 3', solve(True,True,\"x\"*N), [206,\"x\"*N])\ncheck('precondition-before-range fixture 4', solve(False,False,\"\"), [412,\"\"])\ncheck('precondition-before-range fixture 5', solve(True,True,\"\"), [206,\"\"])\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-precondition-before-range","generated_at":"2026-09-29T14:41:15.064262+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 [412, \"\"] if not match_ok else ([206,body] if range_valid else [400,\"\"])","root_cause":"The precondition-before-range decision uses return [400, \"\"] if not range_valid else ([206,body] if match_ok else [412,\"\"]).","sha256":"3ac50258bb0aa73c6d87674534f04751fe147a7fa6ed8fa1f1f25410cc9496b8","title":"Failed write-independent preconditions precede range parsing · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":41.872,"exit_code":1,"observations":[{"actual":[400,""],"check":"precondition-before-range fixture 0","expected":[412,""],"passed":false},{"actual":[412,""],"check":"precondition-before-range fixture 1","expected":[412,""],"passed":true},{"actual":[400,""],"check":"precondition-before-range fixture 2","expected":[400,""],"passed":true},{"actual":[206,"x"],"check":"precondition-before-range fixture 3","expected":[206,"x"],"passed":true},{"actual":[400,""],"check":"precondition-before-range fixture 4","expected":[412,""],"passed":false},{"actual":[206,""],"check":"precondition-before-range fixture 5","expected":[206,""],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"precondition-before-range fixture 0\", \"actual\": [400, \"\"], \"expected\": [412, \"\"], \"passed\": false}, {\"check\": \"precondition-before-range fixture 1\", \"actual\": [412, \"\"], \"expected\": [412, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 2\", \"actual\": [400, \"\"], \"expected\": [400, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 3\", \"actual\": [206, \"x\"], \"expected\": [206, \"x\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 4\", \"actual\": [400, \"\"], \"expected\": [412, \"\"], \"passed\": false}, {\"check\": \"precondition-before-range fixture 5\", \"actual\": [206, \"\"], \"expected\": [206, \"\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.107,"exit_code":1,"observations":[{"actual":[400,""],"check":"precondition-before-range fixture 0","expected":[412,""],"passed":false},{"actual":[412,""],"check":"precondition-before-range fixture 1","expected":[412,""],"passed":true},{"actual":[400,""],"check":"precondition-before-range fixture 2","expected":[400,""],"passed":true},{"actual":[206,"x"],"check":"precondition-before-range fixture 3","expected":[206,"x"],"passed":true},{"actual":[400,""],"check":"precondition-before-range fixture 4","expected":[412,""],"passed":false},{"actual":[206,""],"check":"precondition-before-range fixture 5","expected":[206,""],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"precondition-before-range fixture 0\", \"actual\": [400, \"\"], \"expected\": [412, \"\"], \"passed\": false}, {\"check\": \"precondition-before-range fixture 1\", \"actual\": [412, \"\"], \"expected\": [412, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 2\", \"actual\": [400, \"\"], \"expected\": [400, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 3\", \"actual\": [206, \"x\"], \"expected\": [206, \"x\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 4\", \"actual\": [400, \"\"], \"expected\": [412, \"\"], \"passed\": false}, {\"check\": \"precondition-before-range fixture 5\", \"actual\": [206, \"\"], \"expected\": [206, \"\"], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":39.482,"exit_code":0,"observations":[{"actual":[412,""],"check":"precondition-before-range fixture 0","expected":[412,""],"passed":true},{"actual":[412,""],"check":"precondition-before-range fixture 1","expected":[412,""],"passed":true},{"actual":[400,""],"check":"precondition-before-range fixture 2","expected":[400,""],"passed":true},{"actual":[206,"x"],"check":"precondition-before-range fixture 3","expected":[206,"x"],"passed":true},{"actual":[412,""],"check":"precondition-before-range fixture 4","expected":[412,""],"passed":true},{"actual":[206,""],"check":"precondition-before-range fixture 5","expected":[206,""],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"precondition-before-range fixture 0\", \"actual\": [412, \"\"], \"expected\": [412, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 1\", \"actual\": [412, \"\"], \"expected\": [412, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 2\", \"actual\": [400, \"\"], \"expected\": [400, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 3\", \"actual\": [206, \"x\"], \"expected\": [206, \"x\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 4\", \"actual\": [412, \"\"], \"expected\": [412, \"\"], \"passed\": true}, {\"check\": \"precondition-before-range fixture 5\", \"actual\": [206, \"\"], \"expected\": [206, \"\"], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}