{"abstract":"Explicit identity exclusion prevents uncompressed range fallback.","category":"HTTP ranges","checks":6,"contract":"Local negotiation returns compressed206 if seekable; otherwise identity206 only for positive identity quality, else 406. payload propagates for accepted responses.","contract_signature":"identity_q, compressed_seekable, payload","evaluation_group":"s3-http_ranges-representation","failed_approach":"The partial repair uses return [\"compressed206\",payload] if compressed_seekable else ([\"identity206\",payload] if identity_q>=0 else [\"406\",\"\"]), which still violates the stated contract.","family":"s3-http_ranges-identity-quality-zero","id":"FA-26406","implementations":{"attempt":{"sha256":"6aff8f3c748ea34d3872c8aee114650357d712769efe8c9f842fbfc804f75187","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(identity_q, compressed_seekable, payload):\n    return [\"compressed206\",payload] if compressed_seekable else ([\"identity206\",payload] if identity_q>=0 else [\"406\",\"\"])\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('identity-quality-zero fixture 0', solve(0,False,\"p\"*N), [\"406\",\"\"])\ncheck('identity-quality-zero fixture 1', solve(1,False,\"p\"*N), [\"identity206\",\"p\"*N])\ncheck('identity-quality-zero fixture 2', solve(0,True,\"p\"), [\"compressed206\",\"p\"])\ncheck('identity-quality-zero fixture 3', solve(0.5,False,\"p\"), [\"identity206\",\"p\"])\ncheck('identity-quality-zero fixture 4', solve(1,True,\"\"), [\"compressed206\",\"\"])\ncheck('identity-quality-zero fixture 5', solve(0,False,\"\"), [\"406\",\"\"])\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":"a401bbf69b762bdc90ae8c210327d15e3514663224afc61f4d159077f4e880c5","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(identity_q, compressed_seekable, payload):\n    return [\"compressed206\" if compressed_seekable else \"identity206\",payload]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('identity-quality-zero fixture 0', solve(0,False,\"p\"*N), [\"406\",\"\"])\ncheck('identity-quality-zero fixture 1', solve(1,False,\"p\"*N), [\"identity206\",\"p\"*N])\ncheck('identity-quality-zero fixture 2', solve(0,True,\"p\"), [\"compressed206\",\"p\"])\ncheck('identity-quality-zero fixture 3', solve(0.5,False,\"p\"), [\"identity206\",\"p\"])\ncheck('identity-quality-zero fixture 4', solve(1,True,\"\"), [\"compressed206\",\"\"])\ncheck('identity-quality-zero fixture 5', solve(0,False,\"\"), [\"406\",\"\"])\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":"Deterministic simplified range service, with stipulated local policies and already parsed trusted inputs; not a complete HTTP implementation. 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-http_ranges-identity-quality-zero","generated_at":"2026-09-29T14:41:15.695087+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Range responses combine representation identity, conditional requests, framing, and partial-object state.","root_cause":"The identity-quality-zero decision uses return [\"compressed206\" if compressed_seekable else \"identity206\",payload].","sha256":"e161a3fbc2f928077ba07f4ed886a0eee8381500199473fdc0a7fac2a1fd45b5","title":"Explicit identity exclusion prevents uncompressed range fallback · 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":40.122,"exit_code":1,"observations":[{"actual":["identity206","p"],"check":"identity-quality-zero fixture 0","expected":["406",""],"passed":false},{"actual":["identity206","p"],"check":"identity-quality-zero fixture 1","expected":["identity206","p"],"passed":true},{"actual":["compressed206","p"],"check":"identity-quality-zero fixture 2","expected":["compressed206","p"],"passed":true},{"actual":["identity206","p"],"check":"identity-quality-zero fixture 3","expected":["identity206","p"],"passed":true},{"actual":["compressed206",""],"check":"identity-quality-zero fixture 4","expected":["compressed206",""],"passed":true},{"actual":["identity206",""],"check":"identity-quality-zero fixture 5","expected":["406",""],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"identity-quality-zero fixture 0\", \"actual\": [\"identity206\", \"p\"], \"expected\": [\"406\", \"\"], \"passed\": false}, {\"check\": \"identity-quality-zero fixture 1\", \"actual\": [\"identity206\", \"p\"], \"expected\": [\"identity206\", \"p\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 2\", \"actual\": [\"compressed206\", \"p\"], \"expected\": [\"compressed206\", \"p\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 3\", \"actual\": [\"identity206\", \"p\"], \"expected\": [\"identity206\", \"p\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 4\", \"actual\": [\"compressed206\", \"\"], \"expected\": [\"compressed206\", \"\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 5\", \"actual\": [\"identity206\", \"\"], \"expected\": [\"406\", \"\"], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.877,"exit_code":1,"observations":[{"actual":["identity206","p"],"check":"identity-quality-zero fixture 0","expected":["406",""],"passed":false},{"actual":["identity206","p"],"check":"identity-quality-zero fixture 1","expected":["identity206","p"],"passed":true},{"actual":["compressed206","p"],"check":"identity-quality-zero fixture 2","expected":["compressed206","p"],"passed":true},{"actual":["identity206","p"],"check":"identity-quality-zero fixture 3","expected":["identity206","p"],"passed":true},{"actual":["compressed206",""],"check":"identity-quality-zero fixture 4","expected":["compressed206",""],"passed":true},{"actual":["identity206",""],"check":"identity-quality-zero fixture 5","expected":["406",""],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"identity-quality-zero fixture 0\", \"actual\": [\"identity206\", \"p\"], \"expected\": [\"406\", \"\"], \"passed\": false}, {\"check\": \"identity-quality-zero fixture 1\", \"actual\": [\"identity206\", \"p\"], \"expected\": [\"identity206\", \"p\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 2\", \"actual\": [\"compressed206\", \"p\"], \"expected\": [\"compressed206\", \"p\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 3\", \"actual\": [\"identity206\", \"p\"], \"expected\": [\"identity206\", \"p\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 4\", \"actual\": [\"compressed206\", \"\"], \"expected\": [\"compressed206\", \"\"], \"passed\": true}, {\"check\": \"identity-quality-zero fixture 5\", \"actual\": [\"identity206\", \"\"], \"expected\": [\"406\", \"\"], \"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."}}