{"abstract":"The tab workspace reports an incorrect dragged identity.","category":"Tab interfaces","checks":6,"contract":"A strip drag uses pre-removal boundary indices: remove the dragged view, decrement later boundaries, clamp and insert while retaining active identity.","contract_signature":"x","evaluation_group":"s3-tabs-reorder-drop","failed_approach":"The partial repair x['tabs'][-1] still violates a workspace boundary or normal case.","family":"s3-tab-interfaces-reorder-drop-dragged-identity","id":"FA-35551","implementations":{"attempt":{"sha256":"4ba4c31ba5aa4a78ee2b7f8d8c3448ed5881ada6b195eb38001849232a3f6bc5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    r0 = x['tabs'][-1]\n    r1 = x['tabs'][:x['index']]+x['tabs'][x['index']+1:]\n    r2 = x['boundary']-(x['boundary']>x['index'])\n    r3 = x['boundary'] in (x['index'],x['index']+1)\n    r4 = abs(x['boundary']-(x['boundary']>x['index'])-x['index'])\n    r5 = x['active']\n    return [r0,r1,r2,r3,r4,r5]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = {1: [({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd'], 3, False, 2, 'b'])], 2: [({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0'], 3, False, 2, 'b'])], 3: [({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0', 'background1'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0', 'background1'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 3, False, 2, 'b'])], 4: [({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0', 'background1', 'background2'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0', 'background1', 'background2'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 3, False, 2, 'b'])], 5: [({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0', 'background1', 'background2', 'background3'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 3, False, 2, 'b'])]}\nfor i, (inputs, expected) in enumerate(fixtures[N]):\n    check(\"workspace regression \"+str(i), solve(inputs), expected)\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":"848ed74a805af2485d16b7859e8d29b2babd7716a0ce13b09a3b205224f6894c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    r0 = x['tabs'][0]\n    r1 = x['tabs'][:x['index']]+x['tabs'][x['index']+1:]\n    r2 = x['boundary']-(x['boundary']>x['index'])\n    r3 = x['boundary'] in (x['index'],x['index']+1)\n    r4 = abs(x['boundary']-(x['boundary']>x['index'])-x['index'])\n    r5 = x['active']\n    return [r0,r1,r2,r3,r4,r5]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = {1: [({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd'], 3, False, 2, 'b'])], 2: [({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0'], 3, False, 2, 'b'])], 3: [({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0', 'background1'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0', 'background1'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0', 'background1'], 3, False, 2, 'b'])], 4: [({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0', 'background1', 'background2'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0', 'background1', 'background2'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2'], 3, False, 2, 'b'])], 5: [({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 4, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 3, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 0, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 0, False, 1, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 2, 'active': 'c'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 1, True, 0, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 0, 'boundary': 3, 'active': 'c'}, ['a', ['b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 2, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 3, 'boundary': 1, 'active': 'c'}, ['d', ['a', 'b', 'c', 'background0', 'background1', 'background2', 'background3'], 1, False, 2, 'c']), ({'tabs': ['a', 'b', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 'index': 1, 'boundary': 4, 'active': 'b'}, ['b', ['a', 'c', 'd', 'background0', 'background1', 'background2', 'background3'], 3, False, 2, 'b'])]}\nfor i, (inputs, expected) in enumerate(fixtures[N]):\n    check(\"workspace regression \"+str(i), solve(inputs), expected)\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":"Finite stipulated workspace snapshots only. Independent result fields describe observable obligations, not a full UI runtime. 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":"s3-tab-interfaces-reorder-drop-dragged-identity","generated_at":"2026-09-29T14:42:43.024760+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline tab/panel workspace behavior; no browser or desktop framework is emulated.","root_cause":"The dragged identity decision uses x['tabs'][0] instead of x['tabs'][x['index']].","sha256":"a8866a40117b3d2bbe8c95787dd602ad1925916619ddcb3783b94f336132a4f3","title":"Reorder drop: dragged identity · 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":40.234,"exit_code":1,"observations":[{"actual":["d",["a","c","d"],3,false,2,"c"],"check":"workspace regression 0","expected":["b",["a","c","d"],3,false,2,"c"],"passed":false},{"actual":["d",["a","c","d"],0,false,1,"c"],"check":"workspace regression 1","expected":["b",["a","c","d"],0,false,1,"c"],"passed":false},{"actual":["d",["a","c","d"],1,true,0,"c"],"check":"workspace regression 2","expected":["b",["a","c","d"],1,true,0,"c"],"passed":false},{"actual":["d",["b","c","d"],2,false,2,"c"],"check":"workspace regression 3","expected":["a",["b","c","d"],2,false,2,"c"],"passed":false},{"actual":["d",["a","b","c"],1,false,2,"c"],"check":"workspace regression 4","expected":["d",["a","b","c"],1,false,2,"c"],"passed":true},{"actual":["d",["a","c","d"],3,false,2,"b"],"check":"workspace regression 5","expected":["b",["a","c","d"],3,false,2,"b"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"workspace regression 0\", \"actual\": [\"d\", [\"a\", \"c\", \"d\"], 3, false, 2, \"c\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 3, false, 2, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 1\", \"actual\": [\"d\", [\"a\", \"c\", \"d\"], 0, false, 1, \"c\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 0, false, 1, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 2\", \"actual\": [\"d\", [\"a\", \"c\", \"d\"], 1, true, 0, \"c\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 1, true, 0, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 3\", \"actual\": [\"d\", [\"b\", \"c\", \"d\"], 2, false, 2, \"c\"], \"expected\": [\"a\", [\"b\", \"c\", \"d\"], 2, false, 2, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 4\", \"actual\": [\"d\", [\"a\", \"b\", \"c\"], 1, false, 2, \"c\"], \"expected\": [\"d\", [\"a\", \"b\", \"c\"], 1, false, 2, \"c\"], \"passed\": true}, {\"check\": \"workspace regression 5\", \"actual\": [\"d\", [\"a\", \"c\", \"d\"], 3, false, 2, \"b\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 3, false, 2, \"b\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.122,"exit_code":1,"observations":[{"actual":["a",["a","c","d"],3,false,2,"c"],"check":"workspace regression 0","expected":["b",["a","c","d"],3,false,2,"c"],"passed":false},{"actual":["a",["a","c","d"],0,false,1,"c"],"check":"workspace regression 1","expected":["b",["a","c","d"],0,false,1,"c"],"passed":false},{"actual":["a",["a","c","d"],1,true,0,"c"],"check":"workspace regression 2","expected":["b",["a","c","d"],1,true,0,"c"],"passed":false},{"actual":["a",["b","c","d"],2,false,2,"c"],"check":"workspace regression 3","expected":["a",["b","c","d"],2,false,2,"c"],"passed":true},{"actual":["a",["a","b","c"],1,false,2,"c"],"check":"workspace regression 4","expected":["d",["a","b","c"],1,false,2,"c"],"passed":false},{"actual":["a",["a","c","d"],3,false,2,"b"],"check":"workspace regression 5","expected":["b",["a","c","d"],3,false,2,"b"],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"workspace regression 0\", \"actual\": [\"a\", [\"a\", \"c\", \"d\"], 3, false, 2, \"c\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 3, false, 2, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 1\", \"actual\": [\"a\", [\"a\", \"c\", \"d\"], 0, false, 1, \"c\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 0, false, 1, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 2\", \"actual\": [\"a\", [\"a\", \"c\", \"d\"], 1, true, 0, \"c\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 1, true, 0, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 3\", \"actual\": [\"a\", [\"b\", \"c\", \"d\"], 2, false, 2, \"c\"], \"expected\": [\"a\", [\"b\", \"c\", \"d\"], 2, false, 2, \"c\"], \"passed\": true}, {\"check\": \"workspace regression 4\", \"actual\": [\"a\", [\"a\", \"b\", \"c\"], 1, false, 2, \"c\"], \"expected\": [\"d\", [\"a\", \"b\", \"c\"], 1, false, 2, \"c\"], \"passed\": false}, {\"check\": \"workspace regression 5\", \"actual\": [\"a\", [\"a\", \"c\", \"d\"], 3, false, 2, \"b\"], \"expected\": [\"b\", [\"a\", \"c\", \"d\"], 3, false, 2, \"b\"], \"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."}}