{"abstract":"Inserting without removal duplicates the moved entry.","category":"Media playlist state","checks":4,"contract":"Move source entry to destination index measured in the list after source removal; both indices are valid final positions.","contract_signature":"entries, source, destination","evaluation_group":"xmed-playlist-move-destination-after-removal","failed_approach":"Subtracting one from an already post-removal destination shifts moves too far left.","family":"xmed-playlist-move-destination-after-removal","id":"FA-11086","implementations":{"attempt":{"sha256":"7e5a13e6837b6090a1d5d430f15a6299671f7edf50dd6ddce20af0318cc16f28","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(entries, source, destination):\n    return (entries[:source]+entries[source+1:])[:max(0,destination-1)]+[entries[source]]+(entries[:source]+entries[source+1:])[max(0,destination-1):]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(['a', 'b', 'c', 'd'], 0, 2)),['b', 'c', 'a', 'd'])\ncheck('fixture 2',solve(*(['a', 'b', 'c'], 2, 0)),['c', 'a', 'b'])\ncheck('fixture 3',solve(*(['a'], 0, 0)),['a'])\ncheck('fixture 4',solve(*(['a', 'b', 'c'], 1, 1)),['a', 'b', 'c'])\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":"0907848f550227b55c0f07d74cb61962c2ce709586e36cf2469968071676a964","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(entries, source, destination):\n    return entries[:destination]+[entries[source]]+entries[destination:]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(['a', 'b', 'c', 'd'], 0, 2)),['b', 'c', 'a', 'd'])\ncheck('fixture 2',solve(*(['a', 'b', 'c'], 2, 0)),['c', 'a', 'b'])\ncheck('fixture 3',solve(*(['a'], 0, 0)),['a'])\ncheck('fixture 4',solve(*(['a', 'b', 'c'], 1, 1)),['a', 'b', 'c'])\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":"xmed-playlist-move-destination-after-removal","generated_at":"2026-09-29T14:38:44.909717+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic local media controller stage; metadata and downloaded data are supplied explicitly. No external player, service or codec is required.","root_cause":"Inserting without removal duplicates the moved entry.","sha256":"929c176821347b6063cc54851e88af0ab11627519a8c3c70ef18231891d8dd93","title":"Playlist move destination after removal · case 01","variant":1,"variant_policy":"The five numbered cases rerun the same authored boundary fixtures; they are reproducibility runs, not independent input variants.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":38.848,"exit_code":1,"observations":[{"actual":["b","a","c","d"],"check":"fixture 1","expected":["b","c","a","d"],"passed":false},{"actual":["c","a","b"],"check":"fixture 2","expected":["c","a","b"],"passed":true},{"actual":["a"],"check":"fixture 3","expected":["a"],"passed":true},{"actual":["b","a","c"],"check":"fixture 4","expected":["a","b","c"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"b\", \"a\", \"c\", \"d\"], \"expected\": [\"b\", \"c\", \"a\", \"d\"], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [\"c\", \"a\", \"b\"], \"expected\": [\"c\", \"a\", \"b\"], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [\"b\", \"a\", \"c\"], \"expected\": [\"a\", \"b\", \"c\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.492,"exit_code":1,"observations":[{"actual":["a","b","a","c","d"],"check":"fixture 1","expected":["b","c","a","d"],"passed":false},{"actual":["c","a","b","c"],"check":"fixture 2","expected":["c","a","b"],"passed":false},{"actual":["a","a"],"check":"fixture 3","expected":["a"],"passed":false},{"actual":["a","b","b","c"],"check":"fixture 4","expected":["a","b","c"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [\"a\", \"b\", \"a\", \"c\", \"d\"], \"expected\": [\"b\", \"c\", \"a\", \"d\"], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [\"c\", \"a\", \"b\", \"c\"], \"expected\": [\"c\", \"a\", \"b\"], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [\"a\", \"a\"], \"expected\": [\"a\"], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [\"a\", \"b\", \"b\", \"c\"], \"expected\": [\"a\", \"b\", \"c\"], \"passed\": false}], \"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."}}