{"abstract":"Read cursor advances beyond end by requested rather than consumed count.","category":"Audio frame buffers","checks":4,"contract":"Read up to nonnegative requested mono samples from cursor in [0,length], returning data and next cursor limited by actual available samples.","contract_signature":"samples, cursor, requested","evaluation_group":"xaud-read-cursor-advances-consumed","failed_approach":"Not advancing cursor repeats samples on the next read.","family":"xaud-read-cursor-advances-consumed","id":"FA-10871","implementations":{"attempt":{"sha256":"a1dd65ab42650dd7809080f11a72dee945cab50e17b24d03180b5715e11a1702","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, cursor, requested):\n    return [samples[cursor:cursor+requested],cursor]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2, 3], 2, 5)),[[3], 3])\ncheck('fixture 2',solve(*([1, 2, 3], 0, 2)),[[1, 2], 2])\ncheck('fixture 3',solve(*([], 0, 3)),[[], 0])\ncheck('fixture 4',solve(*([1], 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":"49fc64100137e3dfebb712f8182a55f87f5e22db6c873db0909aac7285bb8a42","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, cursor, requested):\n    return [samples[cursor:cursor+requested],cursor+requested]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2, 3], 2, 5)),[[3], 3])\ncheck('fixture 2',solve(*([1, 2, 3], 0, 2)),[[1, 2], 2])\ncheck('fixture 3',solve(*([], 0, 3)),[[], 0])\ncheck('fixture 4',solve(*([1], 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":" 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":"xaud-read-cursor-advances-consumed","generated_at":"2026-09-29T14:38:42.985093+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.","root_cause":"Read cursor advances beyond end by requested rather than consumed count.","sha256":"e5178dad2ae7d4ca31717a470d6024de5de9f6ad0ba357334119457335d2362c","title":"Read cursor advances consumed · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":42.394,"exit_code":1,"observations":[{"actual":[[3],2],"check":"fixture 1","expected":[[3],3],"passed":false},{"actual":[[1,2],0],"check":"fixture 2","expected":[[1,2],2],"passed":false},{"actual":[[],0],"check":"fixture 3","expected":[[],0],"passed":true},{"actual":[[],0],"check":"fixture 4","expected":[[],0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[3], 2], \"expected\": [[3], 3], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[1, 2], 0], \"expected\": [[1, 2], 2], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [[], 0], \"expected\": [[], 0], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[], 0], \"expected\": [[], 0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.752,"exit_code":1,"observations":[{"actual":[[3],7],"check":"fixture 1","expected":[[3],3],"passed":false},{"actual":[[1,2],2],"check":"fixture 2","expected":[[1,2],2],"passed":true},{"actual":[[],3],"check":"fixture 3","expected":[[],0],"passed":false},{"actual":[[],0],"check":"fixture 4","expected":[[],0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[3], 7], \"expected\": [[3], 3], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[1, 2], 2], \"expected\": [[1, 2], 2], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[], 3], \"expected\": [[], 0], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [[], 0], \"expected\": [[], 0], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}