{"abstract":"Empty edit-list spans do not advance the movie clock and shift later media earlier.","category":"Media timeline seeking","checks":4,"contract":"Edits are [nonnegative movie duration,media start or None for an empty edit]. Annotate each edit with cumulative movie start; empty edits still occupy movie time.","contract_signature":"edits","evaluation_group":"xmed-edit-list-empty-span-advances-movie","failed_approach":"Placing every edit at movie zero overlaps sequential edits.","family":"xmed-edit-list-empty-span-advances-movie","id":"FA-11246","implementations":{"attempt":{"sha256":"ca57e88df427d2305d53478eae8a9dc81dd3b5e0e6dbf34f038a4c94adbcff61","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(edits):\n    return [[0,duration,media] for duration,media in edits]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[2, None], [3, 10]],)),[[0, 2, None], [2, 3, 10]])\ncheck('fixture 2',solve(*([[1, 0], [2, 5]],)),[[0, 1, 0], [1, 2, 5]])\ncheck('fixture 3',solve(*([],)),[])\ncheck('fixture 4',solve(*([[0, None], [1, 0]],)),[[0, 0, None], [0, 1, 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":"723d5867ddb29f9619ded9683c08cfed44d4c0ae5fb001863de8b4db97f32696","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(edits):\n    return [[sum(e[0] for e in edits[:i] if e[1] is not None),duration,media] for i,(duration,media) in enumerate(edits)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[2, None], [3, 10]],)),[[0, 2, None], [2, 3, 10]])\ncheck('fixture 2',solve(*([[1, 0], [2, 5]],)),[[0, 1, 0], [1, 2, 5]])\ncheck('fixture 3',solve(*([],)),[])\ncheck('fixture 4',solve(*([[0, None], [1, 0]],)),[[0, 0, None], [0, 1, 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":"xmed-edit-list-empty-span-advances-movie","generated_at":"2026-09-29T14:38:46.216126+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":"Empty edit-list spans do not advance the movie clock and shift later media earlier.","sha256":"9000b74771c1bd1d3e61adb98528b663c65de593e7bc52dc4ee5dce42437ddfd","title":"Edit list empty span advances movie · 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":37.209,"exit_code":1,"observations":[{"actual":[[0,2,null],[0,3,10]],"check":"fixture 1","expected":[[0,2,null],[2,3,10]],"passed":false},{"actual":[[0,1,0],[0,2,5]],"check":"fixture 2","expected":[[0,1,0],[1,2,5]],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[[0,0,null],[0,1,0]],"check":"fixture 4","expected":[[0,0,null],[0,1,0]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[0, 2, null], [0, 3, 10]], \"expected\": [[0, 2, null], [2, 3, 10]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[0, 1, 0], [0, 2, 5]], \"expected\": [[0, 1, 0], [1, 2, 5]], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[0, 0, null], [0, 1, 0]], \"expected\": [[0, 0, null], [0, 1, 0]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.0,"exit_code":1,"observations":[{"actual":[[0,2,null],[0,3,10]],"check":"fixture 1","expected":[[0,2,null],[2,3,10]],"passed":false},{"actual":[[0,1,0],[1,2,5]],"check":"fixture 2","expected":[[0,1,0],[1,2,5]],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[[0,0,null],[0,1,0]],"check":"fixture 4","expected":[[0,0,null],[0,1,0]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[0, 2, null], [0, 3, 10]], \"expected\": [[0, 2, null], [2, 3, 10]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[0, 1, 0], [1, 2, 5]], \"expected\": [[0, 1, 0], [1, 2, 5]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[0, 0, null], [0, 1, 0]], \"expected\": [[0, 0, null], [0, 1, 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."}}