FA-11076 / Media playlist state / Open access
Skip unavailable selects next playable · case 01
Advancing one index may select an unavailable media item.
ROOT CAUSE
Advancing one index may select an unavailable media item.
VERIFIED REPAIR
Preserve the media contract: Entries are [ID,playable]. Return first playable index strictly after current, without wrapping or replaying earlier entries.
Unsuccessful approach: Searching from the beginning replays history rather than finding a successor.
Case contract
Entries are [ID,playable]. Return first playable index strictly after current, without wrapping or replaying earlier entries.
Why this case matters
A deterministic local media controller stage; metadata and downloaded data are supplied explicitly. No external player, service or codec is required.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(entries, current):
return current+1 if current+1<len(entries) else None
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([['a', True], ['b', False], ['c', True]], 0)),2)
check('fixture 2',solve(*([['a', True], ['b', False]], 0)),None)
check('fixture 3',solve(*([['a', True], ['b', True]], 0)),1)
check('fixture 4',solve(*([['a', True]], 0)),None)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | 1 | 2 | Failed |
| fixture 2 | 1 | None | Failed |
| fixture 3 | 1 | 1 | Passed |
| fixture 4 | None | None | Passed |
SHA-256 / 5459f9e3a7b9a2e38dd155a7bfc6f501c6fa15bb21bed608c3a21e44139e812b
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(entries, current):
return next((i for i,x in enumerate(entries) if x[1]),None)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([['a', True], ['b', False], ['c', True]], 0)),2)
check('fixture 2',solve(*([['a', True], ['b', False]], 0)),None)
check('fixture 3',solve(*([['a', True], ['b', True]], 0)),1)
check('fixture 4',solve(*([['a', True]], 0)),None)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | 0 | 2 | Failed |
| fixture 2 | 0 | None | Failed |
| fixture 3 | 0 | 1 | Failed |
| fixture 4 | 0 | None | Failed |
SHA-256 / 83142783eeb28605b59b73221df14d82708694f9e881a153212d60bb594354ec
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(entries, current):
return next((i for i in range(current+1,len(entries)) if entries[i][1]),None)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([['a', True], ['b', False], ['c', True]], 0)),2)
check('fixture 2',solve(*([['a', True], ['b', False]], 0)),None)
check('fixture 3',solve(*([['a', True], ['b', True]], 0)),1)
check('fixture 4',solve(*([['a', True]], 0)),None)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | 2 | 2 | Passed |
| fixture 2 | None | None | Passed |
| fixture 3 | 1 | 1 | Passed |
| fixture 4 | None | None | Passed |
SHA-256 / 6615f6ef139de8c0e29d428af05a8c0defce15497c61b5846e9b47350e5ab87a
Verification & scope
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.
Observations recorded using Python 3.12.14 at 2026-09-29T14:38:44.791122+00:00.
Case digest / 29c54fdc4a5da6df5362ba9989a7b9b385a8db263499914c44a442cf0489f501