{"abstract":"Horizontal arrow direction ignores right-to-left layout.","category":"Keyboard accessibility","checks":9,"contract":"Home and End select enabled endpoints; horizontal arrows honor directionality and wrap; a removed current item resets to the first enabled item.","contract_signature":"enabled, current, key, rtl","evaluation_group":"xi-roving","failed_approach":"Always reversing also breaks left-to-right layout.","family":"xi-roving-rtl","id":"FA-7891","implementations":{"attempt":{"sha256":"92f24243df5169acba3ad009f8c5bb35e06b8e9f8ccdd108465aa53a7609ea9f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(enabled, current, key, rtl):\n    if not enabled: return None\n    if key == 'Home': return enabled[0]\n    if key == 'End': return enabled[-1]\n    step = (-1 if key == 'Left' else 1) * -1\n    if current not in enabled: return enabled[0]\n    return enabled[(enabled.index(current) + step) % len(enabled)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('home', solve([1,3,7], 3, 'Home', False), 1)\ncheck('end', solve([1,3,7], 3, 'End', False), 7)\ncheck('rtl right', solve([1,3,7], 3, 'Right', True), 1)\ncheck('ltr right', solve([1,3,7], 3, 'Right', False), 7)\ncheck('removed', solve([1,3,7], 8, 'Right', False), 1)\ncheck('wrap', solve([1,3,7], 7, 'Right', False), 1)\ncheck('empty', solve([], 0, 'Home', False), None)\ncheck('parameterized arrow', solve(list(range(N+3)), N, 'Right', False), N+1)\nfor repetition in range(N):\n    check('repeat empty', solve([], 0, 'Home', False), 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":"c866e052de3542c0b0f3b0944335262cf13315e34bbbb669d48539a93073117f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(enabled, current, key, rtl):\n    if not enabled: return None\n    if key == 'Home': return enabled[0]\n    if key == 'End': return enabled[-1]\n    step = (-1 if key == 'Left' else 1) * 1\n    if current not in enabled: return enabled[0]\n    return enabled[(enabled.index(current) + step) % len(enabled)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('home', solve([1,3,7], 3, 'Home', False), 1)\ncheck('end', solve([1,3,7], 3, 'End', False), 7)\ncheck('rtl right', solve([1,3,7], 3, 'Right', True), 1)\ncheck('ltr right', solve([1,3,7], 3, 'Right', False), 7)\ncheck('removed', solve([1,3,7], 8, 'Right', False), 1)\ncheck('wrap', solve([1,3,7], 7, 'Right', False), 1)\ncheck('empty', solve([], 0, 'Home', False), None)\ncheck('parameterized arrow', solve(list(range(N+3)), N, 'Right', False), N+1)\nfor repetition in range(N):\n    check('repeat empty', solve([], 0, 'Home', False), 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":"xi-roving-rtl","generated_at":"2026-09-29T14:38:16.268155+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic model of roving tabindex navigation; this isolates one interface invariant without requiring a browser.","root_cause":"The rtl operation uses `1` where the contract requires `(-1 if rtl else 1)`.","sha256":"11bfbec9c274c1611d90ae934e6fa194f5b4d45209ae759c2509cb962eac1524","title":"Roving tabindex navigation: Horizontal arrow direction ignores right-to-left layout · 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":37.568,"exit_code":1,"observations":[{"actual":1,"check":"home","expected":1,"passed":true},{"actual":7,"check":"end","expected":7,"passed":true},{"actual":1,"check":"rtl right","expected":1,"passed":true},{"actual":1,"check":"ltr right","expected":7,"passed":false},{"actual":1,"check":"removed","expected":1,"passed":true},{"actual":3,"check":"wrap","expected":1,"passed":false},{"actual":null,"check":"empty","expected":null,"passed":true},{"actual":0,"check":"parameterized arrow","expected":2,"passed":false},{"actual":null,"check":"repeat empty","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"home\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"end\", \"actual\": 7, \"expected\": 7, \"passed\": true}, {\"check\": \"rtl right\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"ltr right\", \"actual\": 1, \"expected\": 7, \"passed\": false}, {\"check\": \"removed\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"wrap\", \"actual\": 3, \"expected\": 1, \"passed\": false}, {\"check\": \"empty\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"parameterized arrow\", \"actual\": 0, \"expected\": 2, \"passed\": false}, {\"check\": \"repeat empty\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":44.313,"exit_code":1,"observations":[{"actual":1,"check":"home","expected":1,"passed":true},{"actual":7,"check":"end","expected":7,"passed":true},{"actual":7,"check":"rtl right","expected":1,"passed":false},{"actual":7,"check":"ltr right","expected":7,"passed":true},{"actual":1,"check":"removed","expected":1,"passed":true},{"actual":1,"check":"wrap","expected":1,"passed":true},{"actual":null,"check":"empty","expected":null,"passed":true},{"actual":2,"check":"parameterized arrow","expected":2,"passed":true},{"actual":null,"check":"repeat empty","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"home\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"end\", \"actual\": 7, \"expected\": 7, \"passed\": true}, {\"check\": \"rtl right\", \"actual\": 7, \"expected\": 1, \"passed\": false}, {\"check\": \"ltr right\", \"actual\": 7, \"expected\": 7, \"passed\": true}, {\"check\": \"removed\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"wrap\", \"actual\": 1, \"expected\": 1, \"passed\": true}, {\"check\": \"empty\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"parameterized arrow\", \"actual\": 2, \"expected\": 2, \"passed\": true}, {\"check\": \"repeat empty\", \"actual\": null, \"expected\": 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."}}