{"abstract":"A would-block read does not mean representation EOF.","category":"HTTP ranges","checks":6,"contract":"Return data if nonempty; otherwise wait when blocked, eof when explicit EOF, else idle. The transport never marks blocked and eof simultaneously.","evaluation_group":"s3-http_ranges-stream-transfer","failed_approach":"The partial repair uses return [\"data\",data] if data else ([\"wait\",\"\"] if blocked else [\"eof\",\"\"]), which still violates the stated contract.","family":"s3-http_ranges-stream-empty-read-would-block","id":"FA-26566","implementations":{"attempt":{"sha256":"0d7d00dd3f5239a580d4052245876981b9cfa393515b562589ca31280a50d268","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(data, eof, blocked):\n    return [\"data\",data] if data else ([\"wait\",\"\"] if blocked else [\"eof\",\"\"])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-empty-read-would-block fixture 0', solve(\"\",False,True), [\"wait\",\"\"])\ncheck('stream-empty-read-would-block fixture 1', solve(\"\",False,False), [\"idle\",\"\"])\ncheck('stream-empty-read-would-block fixture 2', solve(\"\",True,False), [\"eof\",\"\"])\ncheck('stream-empty-read-would-block fixture 3', solve(\"p\"*N,False,False), [\"data\",\"p\"*N])\ncheck('stream-empty-read-would-block fixture 4', solve(\"x\",True,False), [\"data\",\"x\"])\ncheck('stream-empty-read-would-block fixture 5', solve(\"p\"*N,False,True), [\"data\",\"p\"*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":"054714645a19ff3c2406f84052021db9265a13a1ca918226ebfcb53ddb6e09f3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(data, eof, blocked):\n    return [\"data\",data] if data else [\"eof\",\"\"]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-empty-read-would-block fixture 0', solve(\"\",False,True), [\"wait\",\"\"])\ncheck('stream-empty-read-would-block fixture 1', solve(\"\",False,False), [\"idle\",\"\"])\ncheck('stream-empty-read-would-block fixture 2', solve(\"\",True,False), [\"eof\",\"\"])\ncheck('stream-empty-read-would-block fixture 3', solve(\"p\"*N,False,False), [\"data\",\"p\"*N])\ncheck('stream-empty-read-would-block fixture 4', solve(\"x\",True,False), [\"data\",\"x\"])\ncheck('stream-empty-read-would-block fixture 5', solve(\"p\"*N,False,True), [\"data\",\"p\"*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"},"fixed":{"sha256":"9a66e775b8b3ff5a0594df1d0a035f6d1ca37988ad6e5fcc57f5be9917fb53b2","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(data, eof, blocked):\n    return [\"data\",data] if data else ([\"wait\",\"\"] if blocked else ([\"eof\",\"\"] if eof else [\"idle\",\"\"]))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('stream-empty-read-would-block fixture 0', solve(\"\",False,True), [\"wait\",\"\"])\ncheck('stream-empty-read-would-block fixture 1', solve(\"\",False,False), [\"idle\",\"\"])\ncheck('stream-empty-read-would-block fixture 2', solve(\"\",True,False), [\"eof\",\"\"])\ncheck('stream-empty-read-would-block fixture 3', solve(\"p\"*N,False,False), [\"data\",\"p\"*N])\ncheck('stream-empty-read-would-block fixture 4', solve(\"x\",True,False), [\"data\",\"x\"])\ncheck('stream-empty-read-would-block fixture 5', solve(\"p\"*N,False,True), [\"data\",\"p\"*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-empty-read-would-block","generated_at":"2026-09-29T14:41:17.071731+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 [\"data\",data] if data else ([\"wait\",\"\"] if blocked else ([\"eof\",\"\"] if eof else [\"idle\",\"\"]))","root_cause":"The stream-empty-read-would-block decision uses return [\"data\",data] if data else [\"eof\",\"\"].","sha256":"78821035ff74b6f9b2ed6badc43fd28396bb861c2e253058e2e7c98c5c794ad0","title":"A would-block read does not mean representation EOF · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.789,"exit_code":1,"observations":[{"actual":["wait",""],"check":"stream-empty-read-would-block fixture 0","expected":["wait",""],"passed":true},{"actual":["eof",""],"check":"stream-empty-read-would-block fixture 1","expected":["idle",""],"passed":false},{"actual":["eof",""],"check":"stream-empty-read-would-block fixture 2","expected":["eof",""],"passed":true},{"actual":["data","p"],"check":"stream-empty-read-would-block fixture 3","expected":["data","p"],"passed":true},{"actual":["data","x"],"check":"stream-empty-read-would-block fixture 4","expected":["data","x"],"passed":true},{"actual":["data","p"],"check":"stream-empty-read-would-block fixture 5","expected":["data","p"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-empty-read-would-block fixture 0\", \"actual\": [\"wait\", \"\"], \"expected\": [\"wait\", \"\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 1\", \"actual\": [\"eof\", \"\"], \"expected\": [\"idle\", \"\"], \"passed\": false}, {\"check\": \"stream-empty-read-would-block fixture 2\", \"actual\": [\"eof\", \"\"], \"expected\": [\"eof\", \"\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 3\", \"actual\": [\"data\", \"p\"], \"expected\": [\"data\", \"p\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 4\", \"actual\": [\"data\", \"x\"], \"expected\": [\"data\", \"x\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 5\", \"actual\": [\"data\", \"p\"], \"expected\": [\"data\", \"p\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":36.63,"exit_code":1,"observations":[{"actual":["eof",""],"check":"stream-empty-read-would-block fixture 0","expected":["wait",""],"passed":false},{"actual":["eof",""],"check":"stream-empty-read-would-block fixture 1","expected":["idle",""],"passed":false},{"actual":["eof",""],"check":"stream-empty-read-would-block fixture 2","expected":["eof",""],"passed":true},{"actual":["data","p"],"check":"stream-empty-read-would-block fixture 3","expected":["data","p"],"passed":true},{"actual":["data","x"],"check":"stream-empty-read-would-block fixture 4","expected":["data","x"],"passed":true},{"actual":["data","p"],"check":"stream-empty-read-would-block fixture 5","expected":["data","p"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-empty-read-would-block fixture 0\", \"actual\": [\"eof\", \"\"], \"expected\": [\"wait\", \"\"], \"passed\": false}, {\"check\": \"stream-empty-read-would-block fixture 1\", \"actual\": [\"eof\", \"\"], \"expected\": [\"idle\", \"\"], \"passed\": false}, {\"check\": \"stream-empty-read-would-block fixture 2\", \"actual\": [\"eof\", \"\"], \"expected\": [\"eof\", \"\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 3\", \"actual\": [\"data\", \"p\"], \"expected\": [\"data\", \"p\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 4\", \"actual\": [\"data\", \"x\"], \"expected\": [\"data\", \"x\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 5\", \"actual\": [\"data\", \"p\"], \"expected\": [\"data\", \"p\"], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.584,"exit_code":0,"observations":[{"actual":["wait",""],"check":"stream-empty-read-would-block fixture 0","expected":["wait",""],"passed":true},{"actual":["idle",""],"check":"stream-empty-read-would-block fixture 1","expected":["idle",""],"passed":true},{"actual":["eof",""],"check":"stream-empty-read-would-block fixture 2","expected":["eof",""],"passed":true},{"actual":["data","p"],"check":"stream-empty-read-would-block fixture 3","expected":["data","p"],"passed":true},{"actual":["data","x"],"check":"stream-empty-read-would-block fixture 4","expected":["data","x"],"passed":true},{"actual":["data","p"],"check":"stream-empty-read-would-block fixture 5","expected":["data","p"],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"stream-empty-read-would-block fixture 0\", \"actual\": [\"wait\", \"\"], \"expected\": [\"wait\", \"\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 1\", \"actual\": [\"idle\", \"\"], \"expected\": [\"idle\", \"\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 2\", \"actual\": [\"eof\", \"\"], \"expected\": [\"eof\", \"\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 3\", \"actual\": [\"data\", \"p\"], \"expected\": [\"data\", \"p\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 4\", \"actual\": [\"data\", \"x\"], \"expected\": [\"data\", \"x\"], \"passed\": true}, {\"check\": \"stream-empty-read-would-block fixture 5\", \"actual\": [\"data\", \"p\"], \"expected\": [\"data\", \"p\"], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}