{"abstract":"An inclusive byte endpoint yields one more byte than endpoint subtraction.","category":"HTTP ranges","checks":4,"contract":"An inclusive byte endpoint yields one more byte than endpoint subtraction: return the result specified by the explicit input/output boundary fixtures.","evaluation_group":"xh-range-inclusive","failed_approach":"The attempted repair uses `end-start+1` and still violates a separate fixture.","family":"xh-range-inclusive","id":"FA-6681","implementations":{"attempt":{"sha256":"f52a392e64614f6a0641fc75b6ada4671a74bab6396a161d6db560357018ef29","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(start, end):\n    return end-start+1\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(2, 2), 1)\", \"check('fixture 2', solve(5, 2), 0)\", \"check('fixture 3', solve(0, 3), 4)\", \"check('fixture 4', solve(0, -1), 0)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"d2e620c149e424b58247ee6be2944eb7952a36e1ac57f8c654f8c8a8b5c957a3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(start, end):\n    return max(0, end-start)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(2, 2), 1)\", \"check('fixture 2', solve(5, 2), 0)\", \"check('fixture 3', solve(0, 3), 4)\", \"check('fixture 4', solve(0, -1), 0)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"637e4144231c5decb550d249dd94536ab1fc01f71110bea6a42272c298062f3a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport ipaddress\nimport re\nfrom urllib.parse import urlsplit, urljoin\nN = 1\nobservations = []\ndef solve(start, end):\n    return max(0, end - start + 1)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\n_fixtures = [\"check('fixture 1', solve(2, 2), 1)\", \"check('fixture 2', solve(5, 2), 0)\", \"check('fixture 3', solve(0, 3), 4)\", \"check('fixture 4', solve(0, -1), 0)\"]\nfor _line in _fixtures[N % len(_fixtures):] + _fixtures[:N % len(_fixtures)]:\n    exec(_line)\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":"Bounded deterministic policy model over validated inputs; not a complete protocol stack or an interoperability claim. The five variants rotate the same explicit fixture set. 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":"xh-range-inclusive","generated_at":"2026-09-29T14:38:04.330037+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"This deterministic http ranges model isolates the range-inclusive policy at a network component boundary.","repair":"Apply the explicit range-inclusive contract, including the tested boundary and negative cases.","root_cause":"The faulty implementation uses `max(0, end-start)` for the range-inclusive decision.","sha256":"bd818f9e7f9f7a01cbfe147abe0327637518601148d8ad20ab15a9aa62a94c9d","title":"An inclusive byte endpoint yields one more byte than endpoint subtraction · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.132,"exit_code":1,"observations":[{"actual":-2,"check":"fixture 2","expected":0,"passed":false},{"actual":4,"check":"fixture 3","expected":4,"passed":true},{"actual":0,"check":"fixture 4","expected":0,"passed":true},{"actual":1,"check":"fixture 1","expected":1,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": -2, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.207,"exit_code":1,"observations":[{"actual":0,"check":"fixture 2","expected":0,"passed":true},{"actual":3,"check":"fixture 3","expected":4,"passed":false},{"actual":0,"check":"fixture 4","expected":0,"passed":true},{"actual":0,"check":"fixture 1","expected":1,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 3, \"expected\": 4, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 0, \"expected\": 1, \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.714,"exit_code":0,"observations":[{"actual":0,"check":"fixture 2","expected":0,"passed":true},{"actual":4,"check":"fixture 3","expected":4,"passed":true},{"actual":0,"check":"fixture 4","expected":0,"passed":true},{"actual":1,"check":"fixture 1","expected":1,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 2\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 4, \"expected\": 4, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 1\", \"actual\": 1, \"expected\": 1, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}