{"abstract":"Removes all equal queued requests after playing one occurrence and produces an incorrect media-control or presentation result.","category":"Media playlist lifecycle","checks":7,"contract":"Consume the first enabled play-next queue occurrence before advancing the playlist. Queue plays do not move the playlist cursor; disabled queued occurrences are discarded. Return [selected ID or None,remaining queue,new playlist cursor]. Queue duplicates are independent requests.","contract_signature":"playlist, cursor, queue, disabled","evaluation_group":"xplay-play-next-queue","failed_approach":"The alternative still fails because it moves the playlist cursor to a queued override.","family":"xplay-play-next-queue-deduplicate-requests","id":"FA-11296","implementations":{"attempt":{"sha256":"83f7f8bda879b5d726c81f4579bf72e1d412d30b1faa3b50d1aed59d896a7eb5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(playlist, cursor, queue, disabled):\n    pending=list(queue)\n    while pending:\n        candidate=pending.pop(0)\n        if candidate in disabled: continue\n        return [candidate,pending,candidate]\n    start=playlist.index(cursor) if cursor in playlist else -1\n    for candidate in playlist[start+1:]:\n        if candidate not in disabled:\n            return [candidate,pending,candidate]\n    return [None,pending,cursor]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('queue has priority', solve(['a', 'b'], 'a', ['x', 'y'], []), ['x', ['y'], 'a'])\ncheck('same track queued twice', solve(['a', 'b'], 'a', ['x', 'x', 'y'], []), ['x', ['x', 'y'], 'a'])\ncheck('disabled queue discarded', solve(['a', 'b'], 'a', ['x', 'y'], ['x']), ['y', [], 'a'])\ncheck('fallback advances cursor', solve(['a', 'b'], 'a', [], []), ['b', [], 'b'])\ncheck('all queued disabled falls back', solve(['a', 'b'], 'a', ['x'], ['x']), ['b', [], 'b'])\ncheck('end has no track', solve(['a'], 'a', [], []), [None, [], 'a'])\ncheck('queue works without playlist', solve([], None, ['x'], []), ['x', [], None])\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":"9a301acbb98887e3755a79879b51c0c3f932ad022d1ec333641338534a2aa90d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(playlist, cursor, queue, disabled):\n    pending=list(queue)\n    while pending:\n        candidate=pending.pop(0)\n        if candidate in disabled: continue\n        return [candidate,[v for v in pending if v!=candidate],cursor]\n    start=playlist.index(cursor) if cursor in playlist else -1\n    for candidate in playlist[start+1:]:\n        if candidate not in disabled:\n            return [candidate,pending,candidate]\n    return [None,pending,cursor]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('queue has priority', solve(['a', 'b'], 'a', ['x', 'y'], []), ['x', ['y'], 'a'])\ncheck('same track queued twice', solve(['a', 'b'], 'a', ['x', 'x', 'y'], []), ['x', ['x', 'y'], 'a'])\ncheck('disabled queue discarded', solve(['a', 'b'], 'a', ['x', 'y'], ['x']), ['y', [], 'a'])\ncheck('fallback advances cursor', solve(['a', 'b'], 'a', [], []), ['b', [], 'b'])\ncheck('all queued disabled falls back', solve(['a', 'b'], 'a', ['x'], ['x']), ['b', [], 'b'])\ncheck('end has no track', solve(['a'], 'a', [], []), [None, [], 'a'])\ncheck('queue works without playlist', solve([], None, ['x'], []), ['x', [], None])\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":"xplay-play-next-queue-deduplicate-requests","generated_at":"2026-09-29T14:38:46.798677+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic in-memory media application model with explicit playlist, timeline or synchronization semantics. Does not implement codecs, transport protocols, rendering hardware or concurrent playback.","root_cause":"Removes all equal queued requests after playing one occurrence. The fixture suite isolates this decision from network delivery and codec details.","sha256":"8c416d6d63de7273a409afd26e38d22c15ddba4efd095b099a820fd68e34c0d0","title":"Play next queue: Removes all equal queued requests after playing one occurrence · case 01","variant":1,"variant_policy":"Numbered cases repeat the same authored boundary fixtures as reproducibility runs, not independent input variants.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":40.622,"exit_code":1,"observations":[{"actual":["x",["y"],"x"],"check":"queue has priority","expected":["x",["y"],"a"],"passed":false},{"actual":["x",["x","y"],"x"],"check":"same track queued twice","expected":["x",["x","y"],"a"],"passed":false},{"actual":["y",[],"y"],"check":"disabled queue discarded","expected":["y",[],"a"],"passed":false},{"actual":["b",[],"b"],"check":"fallback advances cursor","expected":["b",[],"b"],"passed":true},{"actual":["b",[],"b"],"check":"all queued disabled falls back","expected":["b",[],"b"],"passed":true},{"actual":[null,[],"a"],"check":"end has no track","expected":[null,[],"a"],"passed":true},{"actual":["x",[],"x"],"check":"queue works without playlist","expected":["x",[],null],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"queue has priority\", \"actual\": [\"x\", [\"y\"], \"x\"], \"expected\": [\"x\", [\"y\"], \"a\"], \"passed\": false}, {\"check\": \"same track queued twice\", \"actual\": [\"x\", [\"x\", \"y\"], \"x\"], \"expected\": [\"x\", [\"x\", \"y\"], \"a\"], \"passed\": false}, {\"check\": \"disabled queue discarded\", \"actual\": [\"y\", [], \"y\"], \"expected\": [\"y\", [], \"a\"], \"passed\": false}, {\"check\": \"fallback advances cursor\", \"actual\": [\"b\", [], \"b\"], \"expected\": [\"b\", [], \"b\"], \"passed\": true}, {\"check\": \"all queued disabled falls back\", \"actual\": [\"b\", [], \"b\"], \"expected\": [\"b\", [], \"b\"], \"passed\": true}, {\"check\": \"end has no track\", \"actual\": [null, [], \"a\"], \"expected\": [null, [], \"a\"], \"passed\": true}, {\"check\": \"queue works without playlist\", \"actual\": [\"x\", [], \"x\"], \"expected\": [\"x\", [], null], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.183,"exit_code":1,"observations":[{"actual":["x",["y"],"a"],"check":"queue has priority","expected":["x",["y"],"a"],"passed":true},{"actual":["x",["y"],"a"],"check":"same track queued twice","expected":["x",["x","y"],"a"],"passed":false},{"actual":["y",[],"a"],"check":"disabled queue discarded","expected":["y",[],"a"],"passed":true},{"actual":["b",[],"b"],"check":"fallback advances cursor","expected":["b",[],"b"],"passed":true},{"actual":["b",[],"b"],"check":"all queued disabled falls back","expected":["b",[],"b"],"passed":true},{"actual":[null,[],"a"],"check":"end has no track","expected":[null,[],"a"],"passed":true},{"actual":["x",[],null],"check":"queue works without playlist","expected":["x",[],null],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"queue has priority\", \"actual\": [\"x\", [\"y\"], \"a\"], \"expected\": [\"x\", [\"y\"], \"a\"], \"passed\": true}, {\"check\": \"same track queued twice\", \"actual\": [\"x\", [\"y\"], \"a\"], \"expected\": [\"x\", [\"x\", \"y\"], \"a\"], \"passed\": false}, {\"check\": \"disabled queue discarded\", \"actual\": [\"y\", [], \"a\"], \"expected\": [\"y\", [], \"a\"], \"passed\": true}, {\"check\": \"fallback advances cursor\", \"actual\": [\"b\", [], \"b\"], \"expected\": [\"b\", [], \"b\"], \"passed\": true}, {\"check\": \"all queued disabled falls back\", \"actual\": [\"b\", [], \"b\"], \"expected\": [\"b\", [], \"b\"], \"passed\": true}, {\"check\": \"end has no track\", \"actual\": [null, [], \"a\"], \"expected\": [null, [], \"a\"], \"passed\": true}, {\"check\": \"queue works without playlist\", \"actual\": [\"x\", [], null], \"expected\": [\"x\", [], null], \"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."}}