{"abstract":"Updating an early field moves the offsets of later fields in the controlled document model.","category":"Document structure integrity","checks":6,"contract":"Replace disjoint nonempty half-open ranges whose offsets all refer to the original string. Input edits may be unordered.","evaluation_group":"model-0a7f5de16bfa61a4","failed_approach":"Sorting edits left to right makes order deterministic but still invalidates later offsets.","family":"z-documents-field-replacement-offset","id":"FA-11816","implementations":{"attempt":{"sha256":"d323fc3c235c1b1ceb39e8766d300fefb226d181b5abc97b6ecfa7e7081d9daf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(text, fields):\n    for start,end,value in sorted(fields): text=text[:start]+value+text[end:]\n    return text\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [(( 'aXbYc',[(1,2,'q'*N+'q'),(3,4,'Z')]),'a'+'q'*N+'qbZc'), (('',[]),''), (('abc',[(0,3,'')]),''), (('XY',[(1,2,'BBB'),(0,1,'AA')]),'AABBB'), (('abc',[(1,2,'x')]),'axc'), (('XYZ',[(0,1,''),(2,3,'QQ')]),'YQQ')]\nfor i, (args, expected) in enumerate(fixtures):\n    check(\"document fixture \" + str(i), solve(*args), 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":"2bd2dfd3a009075dca3928c69948078b26f99d8d8097149f4d71693c3dd81aaf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(text, fields):\n    for start,end,value in fields: text=text[:start]+value+text[end:]\n    return text\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [(( 'aXbYc',[(1,2,'q'*N+'q'),(3,4,'Z')]),'a'+'q'*N+'qbZc'), (('',[]),''), (('abc',[(0,3,'')]),''), (('XY',[(1,2,'BBB'),(0,1,'AA')]),'AABBB'), (('abc',[(1,2,'x')]),'axc'), (('XYZ',[(0,1,''),(2,3,'QQ')]),'YQQ')]\nfor i, (args, expected) in enumerate(fixtures):\n    check(\"document fixture \" + str(i), solve(*args), 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"},"fixed":{"sha256":"1f42202a4fc14224e09c7d5d89aa69ae25c73e7bd19a63a718d7f803fa682bb3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(text, fields):\n    for start,end,value in sorted(fields,reverse=True): text=text[:start]+value+text[end:]\n    return text\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [(( 'aXbYc',[(1,2,'q'*N+'q'),(3,4,'Z')]),'a'+'q'*N+'qbZc'), (('',[]),''), (('abc',[(0,3,'')]),''), (('XY',[(1,2,'BBB'),(0,1,'AA')]),'AABBB'), (('abc',[(1,2,'x')]),'axc'), (('XYZ',[(0,1,''),(2,3,'QQ')]),'YQQ')]\nfor i, (args, expected) in enumerate(fixtures):\n    check(\"document fixture \" + str(i), solve(*args), 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":"An offline simplified document model, not a claim of conformance to any office file format. 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":"z-documents-field-replacement-offset","generated_at":"2026-09-29T14:38:51.175840+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Structured editing must preserve document semantics independently of visual rendering.","repair":"Apply replacements from highest original offset to lowest.","root_cause":"Original-document field offsets are applied to an already length-modified buffer.","sha256":"144d2c17387417bbaf12f187bdbb256d024c221f731b76bb4a083246b6e2ea30","title":"Updating an early field moves the offsets of later fields · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.265,"exit_code":1,"observations":[{"actual":"aqqZYc","check":"document fixture 0","expected":"aqqbZc","passed":false},{"actual":"","check":"document fixture 1","expected":"","passed":true},{"actual":"","check":"document fixture 2","expected":"","passed":true},{"actual":"ABBBY","check":"document fixture 3","expected":"AABBB","passed":false},{"actual":"axc","check":"document fixture 4","expected":"axc","passed":true},{"actual":"YZQQ","check":"document fixture 5","expected":"YQQ","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"document fixture 0\", \"actual\": \"aqqZYc\", \"expected\": \"aqqbZc\", \"passed\": false}, {\"check\": \"document fixture 1\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"document fixture 2\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"document fixture 3\", \"actual\": \"ABBBY\", \"expected\": \"AABBB\", \"passed\": false}, {\"check\": \"document fixture 4\", \"actual\": \"axc\", \"expected\": \"axc\", \"passed\": true}, {\"check\": \"document fixture 5\", \"actual\": \"YZQQ\", \"expected\": \"YQQ\", \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.959,"exit_code":1,"observations":[{"actual":"aqqZYc","check":"document fixture 0","expected":"aqqbZc","passed":false},{"actual":"","check":"document fixture 1","expected":"","passed":true},{"actual":"","check":"document fixture 2","expected":"","passed":true},{"actual":"AABBB","check":"document fixture 3","expected":"AABBB","passed":true},{"actual":"axc","check":"document fixture 4","expected":"axc","passed":true},{"actual":"YZQQ","check":"document fixture 5","expected":"YQQ","passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"document fixture 0\", \"actual\": \"aqqZYc\", \"expected\": \"aqqbZc\", \"passed\": false}, {\"check\": \"document fixture 1\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"document fixture 2\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"document fixture 3\", \"actual\": \"AABBB\", \"expected\": \"AABBB\", \"passed\": true}, {\"check\": \"document fixture 4\", \"actual\": \"axc\", \"expected\": \"axc\", \"passed\": true}, {\"check\": \"document fixture 5\", \"actual\": \"YZQQ\", \"expected\": \"YQQ\", \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.416,"exit_code":0,"observations":[{"actual":"aqqbZc","check":"document fixture 0","expected":"aqqbZc","passed":true},{"actual":"","check":"document fixture 1","expected":"","passed":true},{"actual":"","check":"document fixture 2","expected":"","passed":true},{"actual":"AABBB","check":"document fixture 3","expected":"AABBB","passed":true},{"actual":"axc","check":"document fixture 4","expected":"axc","passed":true},{"actual":"YQQ","check":"document fixture 5","expected":"YQQ","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"document fixture 0\", \"actual\": \"aqqbZc\", \"expected\": \"aqqbZc\", \"passed\": true}, {\"check\": \"document fixture 1\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"document fixture 2\", \"actual\": \"\", \"expected\": \"\", \"passed\": true}, {\"check\": \"document fixture 3\", \"actual\": \"AABBB\", \"expected\": \"AABBB\", \"passed\": true}, {\"check\": \"document fixture 4\", \"actual\": \"axc\", \"expected\": \"axc\", \"passed\": true}, {\"check\": \"document fixture 5\", \"actual\": \"YQQ\", \"expected\": \"YQQ\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}