{"abstract":"Sibling prefixes mark unrelated navigation items active.","category":"Client navigation","checks":11,"contract":"Ignore URL query and fragment; normalize trailing slashes with root preserved; honor case policy; section matches require a slash boundary and root matches exactly.","evaluation_group":"xi-route-active","failed_approach":"Substring matching also activates nested unrelated segment names.","family":"xi-route-active-segment","id":"FA-8676","implementations":{"attempt":{"sha256":"2965d05e45eb5ad29245c5956cb9343830832df57e47b10cec642a7da2e5ea00","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(path, link, exact, case_sensitive):\n    path = path.split('?', 1)[0].split('#', 1)[0]\n    link = link.rstrip('/') or '/'\n    path = path.rstrip('/') or '/'\n    if not case_sensitive: path, link = path.casefold(), link.casefold()\n    if exact or link == '/': return path == link\n    return path == link or link in path\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('query', solve('/docs?x=1', '/docs', True, True), True)\ncheck('fragment', solve('/docs#intro', '/docs', True, True), True)\ncheck('slash', solve('/docs', '/docs/', True, True), True)\ncheck('root', solve('/docs', '/', False, True), False)\ncheck('root itself', solve('/', '/', True, True), True)\ncheck('fold', solve(\"/DOCS\", \"/docs\", True, False), True)\ncheck('sensitive', solve(\"/DOCS\", \"/docs\", True, True), False)\ncheck('child', solve('/docs/a', '/docs', False, True), True)\ncheck('prefix sibling', solve('/docstring', '/docs', False, True), False)\ncheck('parameterized route segment', solve('/section'+str(N)+'/child','/section'+str(N),False,True), True)\nfor repetition in range(N):\n    check('repeat prefix sibling', solve('/docstring', '/docs', False, True), False)\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":"ee64f88d5b7f9d5e44d6bd53c93087bb51b8156baac29ea7b33a2c06116d4302","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(path, link, exact, case_sensitive):\n    path = path.split('?', 1)[0].split('#', 1)[0]\n    link = link.rstrip('/') or '/'\n    path = path.rstrip('/') or '/'\n    if not case_sensitive: path, link = path.casefold(), link.casefold()\n    if exact or link == '/': return path == link\n    return path == link or path.startswith(link)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('query', solve('/docs?x=1', '/docs', True, True), True)\ncheck('fragment', solve('/docs#intro', '/docs', True, True), True)\ncheck('slash', solve('/docs', '/docs/', True, True), True)\ncheck('root', solve('/docs', '/', False, True), False)\ncheck('root itself', solve('/', '/', True, True), True)\ncheck('fold', solve(\"/DOCS\", \"/docs\", True, False), True)\ncheck('sensitive', solve(\"/DOCS\", \"/docs\", True, True), False)\ncheck('child', solve('/docs/a', '/docs', False, True), True)\ncheck('prefix sibling', solve('/docstring', '/docs', False, True), False)\ncheck('parameterized route segment', solve('/section'+str(N)+'/child','/section'+str(N),False,True), True)\nfor repetition in range(N):\n    check('repeat prefix sibling', solve('/docstring', '/docs', False, True), False)\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":"5f4fba5b804be1fd36d31301a615d617455f49d9f15a48c72b61e31b818c9a6b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(path, link, exact, case_sensitive):\n    path = path.split('?', 1)[0].split('#', 1)[0]\n    link = link.rstrip('/') or '/'\n    path = path.rstrip('/') or '/'\n    if not case_sensitive: path, link = path.casefold(), link.casefold()\n    if exact or link == '/': return path == link\n    return path == link or path.startswith(link + '/')\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('query', solve('/docs?x=1', '/docs', True, True), True)\ncheck('fragment', solve('/docs#intro', '/docs', True, True), True)\ncheck('slash', solve('/docs', '/docs/', True, True), True)\ncheck('root', solve('/docs', '/', False, True), False)\ncheck('root itself', solve('/', '/', True, True), True)\ncheck('fold', solve(\"/DOCS\", \"/docs\", True, False), True)\ncheck('sensitive', solve(\"/DOCS\", \"/docs\", True, True), False)\ncheck('child', solve('/docs/a', '/docs', False, True), True)\ncheck('prefix sibling', solve('/docstring', '/docs', False, True), False)\ncheck('parameterized route segment', solve('/section'+str(N)+'/child','/section'+str(N),False,True), True)\nfor repetition in range(N):\n    check('repeat prefix sibling', solve('/docstring', '/docs', False, True), False)\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-route-active-segment","generated_at":"2026-09-29T14:38:23.444198+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic model of navigation active-link matching; this isolates one interface invariant without requiring a browser.","repair":"Implement the segment operation as `path.startswith(link + '/')`.","root_cause":"The segment operation uses `path.startswith(link)` where the contract requires `path.startswith(link + '/')`.","sha256":"abc5128f2c0eb77c526ad4cd7829a6c87571d891f4c7df7c913142c84575134d","title":"Navigation active-link matching: Sibling prefixes mark unrelated navigation items active · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":35.087,"exit_code":1,"observations":[{"actual":true,"check":"query","expected":true,"passed":true},{"actual":true,"check":"fragment","expected":true,"passed":true},{"actual":true,"check":"slash","expected":true,"passed":true},{"actual":false,"check":"root","expected":false,"passed":true},{"actual":true,"check":"root itself","expected":true,"passed":true},{"actual":true,"check":"fold","expected":true,"passed":true},{"actual":false,"check":"sensitive","expected":false,"passed":true},{"actual":true,"check":"child","expected":true,"passed":true},{"actual":true,"check":"prefix sibling","expected":false,"passed":false},{"actual":true,"check":"parameterized route segment","expected":true,"passed":true},{"actual":true,"check":"repeat prefix sibling","expected":false,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"query\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fragment\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"slash\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"root\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"root itself\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fold\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"sensitive\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"child\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"prefix sibling\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"parameterized route segment\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"repeat prefix sibling\", \"actual\": true, \"expected\": false, \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.26,"exit_code":1,"observations":[{"actual":true,"check":"query","expected":true,"passed":true},{"actual":true,"check":"fragment","expected":true,"passed":true},{"actual":true,"check":"slash","expected":true,"passed":true},{"actual":false,"check":"root","expected":false,"passed":true},{"actual":true,"check":"root itself","expected":true,"passed":true},{"actual":true,"check":"fold","expected":true,"passed":true},{"actual":false,"check":"sensitive","expected":false,"passed":true},{"actual":true,"check":"child","expected":true,"passed":true},{"actual":true,"check":"prefix sibling","expected":false,"passed":false},{"actual":true,"check":"parameterized route segment","expected":true,"passed":true},{"actual":true,"check":"repeat prefix sibling","expected":false,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"query\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fragment\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"slash\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"root\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"root itself\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fold\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"sensitive\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"child\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"prefix sibling\", \"actual\": true, \"expected\": false, \"passed\": false}, {\"check\": \"parameterized route segment\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"repeat prefix sibling\", \"actual\": true, \"expected\": false, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":37.961,"exit_code":0,"observations":[{"actual":true,"check":"query","expected":true,"passed":true},{"actual":true,"check":"fragment","expected":true,"passed":true},{"actual":true,"check":"slash","expected":true,"passed":true},{"actual":false,"check":"root","expected":false,"passed":true},{"actual":true,"check":"root itself","expected":true,"passed":true},{"actual":true,"check":"fold","expected":true,"passed":true},{"actual":false,"check":"sensitive","expected":false,"passed":true},{"actual":true,"check":"child","expected":true,"passed":true},{"actual":false,"check":"prefix sibling","expected":false,"passed":true},{"actual":true,"check":"parameterized route segment","expected":true,"passed":true},{"actual":false,"check":"repeat prefix sibling","expected":false,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"query\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fragment\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"slash\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"root\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"root itself\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"fold\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"sensitive\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"child\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"prefix sibling\", \"actual\": false, \"expected\": false, \"passed\": true}, {\"check\": \"parameterized route segment\", \"actual\": true, \"expected\": true, \"passed\": true}, {\"check\": \"repeat prefix sibling\", \"actual\": false, \"expected\": false, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}