{"abstract":"A client serializes a typed range request plan: multiple members share a single comma-separated field.","category":"HTTP ranges","checks":7,"contract":"Input x contains selectors [kind,a,b], validator [tag|date,value] or null, and accept encoding policy. Closed selectors serialize a-b, open selectors a-, suffix selectors -a, in input order. Empty selectors omit Range and If-Range. Tag validators are quoted opaque ASCII strings without quotes/backslashes; dates are already formatted and remain unquoted. Identity-only policy emits Accept-Encoding identity. Return ordered [header,value] pairs.","evaluation_group":"s3-http_ranges-outbound-range-request","failed_approach":"The partial repair uses members=[]\nfor kind,a,b in x['selectors']:\n    if kind=='closed': members.append(str(a)+'-'+str(b))\n    elif kind=='open': members.append(str(a)+'-')\n    elif kind=='suffix': members.append('-'+str(a))\nheaders=[]\nif members:\n    headers.append(['Range','bytes='+',bytes='.join(members)])\n    if x['validator'] is not None:\n        kind,value=x['validator']\n        headers.append(['If-Range','\"'+value+'\"' if kind=='tag' else value])\nif x['identity']: headers.append(['Accept-Encoding','identity'])\nreturn headers, which still violates the stated contract.","family":"s3-http_ranges-outbound-range-request-member-separator","id":"FA-27011","implementations":{"attempt":{"sha256":"46a2021ae56cfc1f1af7dfebf6e13f9a400d53ef1de55c32d6ce7bdb789080cc","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    members=[]\n    for kind,a,b in x['selectors']:\n        if kind=='closed': members.append(str(a)+'-'+str(b))\n        elif kind=='open': members.append(str(a)+'-')\n        elif kind=='suffix': members.append('-'+str(a))\n    headers=[]\n    if members:\n        headers.append(['Range','bytes='+',bytes='.join(members)])\n        if x['validator'] is not None:\n            kind,value=x['validator']\n            headers.append(['If-Range','\"'+value+'\"' if kind=='tag' else value])\n    if x['identity']: headers.append(['Accept-Encoding','identity'])\n    return headers\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('member-separator fixture 0', json.loads(json.dumps(solve({'selectors':[['closed',0,N],['suffix',2,None]],'validator':['tag','rev'],'identity':True}))), json.loads(json.dumps([['Range',\"bytes=0-\"+str(N)+\",-2\"],['If-Range','\"rev\"'],['Accept-Encoding','identity']])))\ncheck('member-separator fixture 1', json.loads(json.dumps(solve({'selectors':[['open',5,None]],'validator':['date','Mon, 01 Jan 2001 00:00:00 GMT'],'identity':False}))), json.loads(json.dumps([['Range','bytes=5-'],['If-Range','Mon, 01 Jan 2001 00:00:00 GMT']])))\ncheck('member-separator fixture 2', json.loads(json.dumps(solve({'selectors':[],'validator':['tag','rev'],'identity':False}))), json.loads(json.dumps([])))\ncheck('member-separator fixture 3', json.loads(json.dumps(solve({'selectors':[['closed',9,9],['closed',0,0]],'validator':None,'identity':False}))), json.loads(json.dumps([['Range','bytes=9-9,0-0']])))\ncheck('member-separator fixture 4', json.loads(json.dumps(solve({'selectors':[['suffix',0,None]],'validator':['tag',''],'identity':False}))), json.loads(json.dumps([['Range','bytes=-0'],['If-Range','\"\"']])))\ncheck('member-separator fixture 5', json.loads(json.dumps(solve({'selectors':[],'validator':None,'identity':True}))), json.loads(json.dumps([['Accept-Encoding','identity']])))\ncheck('member-separator fixture 6', json.loads(json.dumps(solve({'selectors':[['open',0,None]],'validator':None,'identity':False}))), json.loads(json.dumps([['Range','bytes=0-']])))\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":"7424c7d69cd90fd655eb5cbcdb64382d1c3a54107c23d354b02b1b9ee741a328","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    members=[]\n    for kind,a,b in x['selectors']:\n        if kind=='closed': members.append(str(a)+'-'+str(b))\n        elif kind=='open': members.append(str(a)+'-')\n        elif kind=='suffix': members.append('-'+str(a))\n    headers=[]\n    if members:\n        headers.append(['Range','bytes='+' '.join(members)])\n        if x['validator'] is not None:\n            kind,value=x['validator']\n            headers.append(['If-Range','\"'+value+'\"' if kind=='tag' else value])\n    if x['identity']: headers.append(['Accept-Encoding','identity'])\n    return headers\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('member-separator fixture 0', json.loads(json.dumps(solve({'selectors':[['closed',0,N],['suffix',2,None]],'validator':['tag','rev'],'identity':True}))), json.loads(json.dumps([['Range',\"bytes=0-\"+str(N)+\",-2\"],['If-Range','\"rev\"'],['Accept-Encoding','identity']])))\ncheck('member-separator fixture 1', json.loads(json.dumps(solve({'selectors':[['open',5,None]],'validator':['date','Mon, 01 Jan 2001 00:00:00 GMT'],'identity':False}))), json.loads(json.dumps([['Range','bytes=5-'],['If-Range','Mon, 01 Jan 2001 00:00:00 GMT']])))\ncheck('member-separator fixture 2', json.loads(json.dumps(solve({'selectors':[],'validator':['tag','rev'],'identity':False}))), json.loads(json.dumps([])))\ncheck('member-separator fixture 3', json.loads(json.dumps(solve({'selectors':[['closed',9,9],['closed',0,0]],'validator':None,'identity':False}))), json.loads(json.dumps([['Range','bytes=9-9,0-0']])))\ncheck('member-separator fixture 4', json.loads(json.dumps(solve({'selectors':[['suffix',0,None]],'validator':['tag',''],'identity':False}))), json.loads(json.dumps([['Range','bytes=-0'],['If-Range','\"\"']])))\ncheck('member-separator fixture 5', json.loads(json.dumps(solve({'selectors':[],'validator':None,'identity':True}))), json.loads(json.dumps([['Accept-Encoding','identity']])))\ncheck('member-separator fixture 6', json.loads(json.dumps(solve({'selectors':[['open',0,None]],'validator':None,'identity':False}))), json.loads(json.dumps([['Range','bytes=0-']])))\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":"1d677959b38d8a2204486becd2103fd038af8bd4da66a702cf22d59333caf2ba","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    members=[]\n    for kind,a,b in x['selectors']:\n        if kind=='closed': members.append(str(a)+'-'+str(b))\n        elif kind=='open': members.append(str(a)+'-')\n        elif kind=='suffix': members.append('-'+str(a))\n    headers=[]\n    if members:\n        headers.append(['Range','bytes='+','.join(members)])\n        if x['validator'] is not None:\n            kind,value=x['validator']\n            headers.append(['If-Range','\"'+value+'\"' if kind=='tag' else value])\n    if x['identity']: headers.append(['Accept-Encoding','identity'])\n    return headers\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('member-separator fixture 0', json.loads(json.dumps(solve({'selectors':[['closed',0,N],['suffix',2,None]],'validator':['tag','rev'],'identity':True}))), json.loads(json.dumps([['Range',\"bytes=0-\"+str(N)+\",-2\"],['If-Range','\"rev\"'],['Accept-Encoding','identity']])))\ncheck('member-separator fixture 1', json.loads(json.dumps(solve({'selectors':[['open',5,None]],'validator':['date','Mon, 01 Jan 2001 00:00:00 GMT'],'identity':False}))), json.loads(json.dumps([['Range','bytes=5-'],['If-Range','Mon, 01 Jan 2001 00:00:00 GMT']])))\ncheck('member-separator fixture 2', json.loads(json.dumps(solve({'selectors':[],'validator':['tag','rev'],'identity':False}))), json.loads(json.dumps([])))\ncheck('member-separator fixture 3', json.loads(json.dumps(solve({'selectors':[['closed',9,9],['closed',0,0]],'validator':None,'identity':False}))), json.loads(json.dumps([['Range','bytes=9-9,0-0']])))\ncheck('member-separator fixture 4', json.loads(json.dumps(solve({'selectors':[['suffix',0,None]],'validator':['tag',''],'identity':False}))), json.loads(json.dumps([['Range','bytes=-0'],['If-Range','\"\"']])))\ncheck('member-separator fixture 5', json.loads(json.dumps(solve({'selectors':[],'validator':None,'identity':True}))), json.loads(json.dumps([['Accept-Encoding','identity']])))\ncheck('member-separator fixture 6', json.loads(json.dumps(solve({'selectors':[['open',0,None]],'validator':None,'identity':False}))), json.loads(json.dumps([['Range','bytes=0-']])))\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-outbound-range-request-member-separator","generated_at":"2026-09-29T14:41:21.293624+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.","repair":"Apply the bounded decision exactly: members=[]\nfor kind,a,b in x['selectors']:\n    if kind=='closed': members.append(str(a)+'-'+str(b))\n    elif kind=='open': members.append(str(a)+'-')\n    elif kind=='suffix': members.append('-'+str(a))\nheaders=[]\nif members:\n    headers.append(['Range','bytes='+','.join(members)])\n    if x['validator'] is not None:\n        kind,value=x['validator']\n        headers.append(['If-Range','\"'+value+'\"' if kind=='tag' else value])\nif x['identity']: headers.append(['Accept-Encoding','identity'])\nreturn headers","root_cause":"The outbound-range-request-member-separator decision uses members=[]\nfor kind,a,b in x['selectors']:\n    if kind=='closed': members.append(str(a)+'-'+str(b))\n    elif kind=='open': members.append(str(a)+'-')\n    elif kind=='suffix': members.append('-'+str(a))\nheaders=[]\nif members:\n    headers.append(['Range','bytes='+' '.join(members)])\n    if x['validator'] is not None:\n        kind,value=x['validator']\n        headers.append(['If-Range','\"'+value+'\"' if kind=='tag' else value])\nif x['identity']: headers.append(['Accept-Encoding','identity'])\nreturn headers.","sha256":"ac4f10a3d4f71fba7c67664adce41364c9d38d0f43d595ab962b247a56cf192a","title":"A client serializes a typed range request plan: multiple members share a single comma-separated field · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":67.01,"exit_code":1,"observations":[{"actual":[["Range","bytes=0-1,bytes=-2"],["If-Range","\"rev\""],["Accept-Encoding","identity"]],"check":"member-separator fixture 0","expected":[["Range","bytes=0-1,-2"],["If-Range","\"rev\""],["Accept-Encoding","identity"]],"passed":false},{"actual":[["Range","bytes=5-"],["If-Range","Mon, 01 Jan 2001 00:00:00 GMT"]],"check":"member-separator fixture 1","expected":[["Range","bytes=5-"],["If-Range","Mon, 01 Jan 2001 00:00:00 GMT"]],"passed":true},{"actual":[],"check":"member-separator fixture 2","expected":[],"passed":true},{"actual":[["Range","bytes=9-9,bytes=0-0"]],"check":"member-separator fixture 3","expected":[["Range","bytes=9-9,0-0"]],"passed":false},{"actual":[["Range","bytes=-0"],["If-Range","\"\""]],"check":"member-separator fixture 4","expected":[["Range","bytes=-0"],["If-Range","\"\""]],"passed":true},{"actual":[["Accept-Encoding","identity"]],"check":"member-separator fixture 5","expected":[["Accept-Encoding","identity"]],"passed":true},{"actual":[["Range","bytes=0-"]],"check":"member-separator fixture 6","expected":[["Range","bytes=0-"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"member-separator fixture 0\", \"actual\": [[\"Range\", \"bytes=0-1,bytes=-2\"], [\"If-Range\", \"\\\"rev\\\"\"], [\"Accept-Encoding\", \"identity\"]], \"expected\": [[\"Range\", \"bytes=0-1,-2\"], [\"If-Range\", \"\\\"rev\\\"\"], [\"Accept-Encoding\", \"identity\"]], \"passed\": false}, {\"check\": \"member-separator fixture 1\", \"actual\": [[\"Range\", \"bytes=5-\"], [\"If-Range\", \"Mon, 01 Jan 2001 00:00:00 GMT\"]], \"expected\": [[\"Range\", \"bytes=5-\"], [\"If-Range\", \"Mon, 01 Jan 2001 00:00:00 GMT\"]], \"passed\": true}, {\"check\": \"member-separator fixture 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"member-separator fixture 3\", \"actual\": [[\"Range\", \"bytes=9-9,bytes=0-0\"]], \"expected\": [[\"Range\", \"bytes=9-9,0-0\"]], \"passed\": false}, {\"check\": \"member-separator fixture 4\", \"actual\": [[\"Range\", \"bytes=-0\"], [\"If-Range\", \"\\\"\\\"\"]], \"expected\": [[\"Range\", \"bytes=-0\"], [\"If-Range\", \"\\\"\\\"\"]], \"passed\": true}, {\"check\": \"member-separator fixture 5\", \"actual\": [[\"Accept-Encoding\", \"identity\"]], \"expected\": [[\"Accept-Encoding\", \"identity\"]], \"passed\": true}, {\"check\": \"member-separator fixture 6\", \"actual\": [[\"Range\", \"bytes=0-\"]], \"expected\": [[\"Range\", \"bytes=0-\"]], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":46.194,"exit_code":1,"observations":[{"actual":[["Range","bytes=0-1 -2"],["If-Range","\"rev\""],["Accept-Encoding","identity"]],"check":"member-separator fixture 0","expected":[["Range","bytes=0-1,-2"],["If-Range","\"rev\""],["Accept-Encoding","identity"]],"passed":false},{"actual":[["Range","bytes=5-"],["If-Range","Mon, 01 Jan 2001 00:00:00 GMT"]],"check":"member-separator fixture 1","expected":[["Range","bytes=5-"],["If-Range","Mon, 01 Jan 2001 00:00:00 GMT"]],"passed":true},{"actual":[],"check":"member-separator fixture 2","expected":[],"passed":true},{"actual":[["Range","bytes=9-9 0-0"]],"check":"member-separator fixture 3","expected":[["Range","bytes=9-9,0-0"]],"passed":false},{"actual":[["Range","bytes=-0"],["If-Range","\"\""]],"check":"member-separator fixture 4","expected":[["Range","bytes=-0"],["If-Range","\"\""]],"passed":true},{"actual":[["Accept-Encoding","identity"]],"check":"member-separator fixture 5","expected":[["Accept-Encoding","identity"]],"passed":true},{"actual":[["Range","bytes=0-"]],"check":"member-separator fixture 6","expected":[["Range","bytes=0-"]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"member-separator fixture 0\", \"actual\": [[\"Range\", \"bytes=0-1 -2\"], [\"If-Range\", \"\\\"rev\\\"\"], [\"Accept-Encoding\", \"identity\"]], \"expected\": [[\"Range\", \"bytes=0-1,-2\"], [\"If-Range\", \"\\\"rev\\\"\"], [\"Accept-Encoding\", \"identity\"]], \"passed\": false}, {\"check\": \"member-separator fixture 1\", \"actual\": [[\"Range\", \"bytes=5-\"], [\"If-Range\", \"Mon, 01 Jan 2001 00:00:00 GMT\"]], \"expected\": [[\"Range\", \"bytes=5-\"], [\"If-Range\", \"Mon, 01 Jan 2001 00:00:00 GMT\"]], \"passed\": true}, {\"check\": \"member-separator fixture 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"member-separator fixture 3\", \"actual\": [[\"Range\", \"bytes=9-9 0-0\"]], \"expected\": [[\"Range\", \"bytes=9-9,0-0\"]], \"passed\": false}, {\"check\": \"member-separator fixture 4\", \"actual\": [[\"Range\", \"bytes=-0\"], [\"If-Range\", \"\\\"\\\"\"]], \"expected\": [[\"Range\", \"bytes=-0\"], [\"If-Range\", \"\\\"\\\"\"]], \"passed\": true}, {\"check\": \"member-separator fixture 5\", \"actual\": [[\"Accept-Encoding\", \"identity\"]], \"expected\": [[\"Accept-Encoding\", \"identity\"]], \"passed\": true}, {\"check\": \"member-separator fixture 6\", \"actual\": [[\"Range\", \"bytes=0-\"]], \"expected\": [[\"Range\", \"bytes=0-\"]], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":39.371,"exit_code":0,"observations":[{"actual":[["Range","bytes=0-1,-2"],["If-Range","\"rev\""],["Accept-Encoding","identity"]],"check":"member-separator fixture 0","expected":[["Range","bytes=0-1,-2"],["If-Range","\"rev\""],["Accept-Encoding","identity"]],"passed":true},{"actual":[["Range","bytes=5-"],["If-Range","Mon, 01 Jan 2001 00:00:00 GMT"]],"check":"member-separator fixture 1","expected":[["Range","bytes=5-"],["If-Range","Mon, 01 Jan 2001 00:00:00 GMT"]],"passed":true},{"actual":[],"check":"member-separator fixture 2","expected":[],"passed":true},{"actual":[["Range","bytes=9-9,0-0"]],"check":"member-separator fixture 3","expected":[["Range","bytes=9-9,0-0"]],"passed":true},{"actual":[["Range","bytes=-0"],["If-Range","\"\""]],"check":"member-separator fixture 4","expected":[["Range","bytes=-0"],["If-Range","\"\""]],"passed":true},{"actual":[["Accept-Encoding","identity"]],"check":"member-separator fixture 5","expected":[["Accept-Encoding","identity"]],"passed":true},{"actual":[["Range","bytes=0-"]],"check":"member-separator fixture 6","expected":[["Range","bytes=0-"]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"member-separator fixture 0\", \"actual\": [[\"Range\", \"bytes=0-1,-2\"], [\"If-Range\", \"\\\"rev\\\"\"], [\"Accept-Encoding\", \"identity\"]], \"expected\": [[\"Range\", \"bytes=0-1,-2\"], [\"If-Range\", \"\\\"rev\\\"\"], [\"Accept-Encoding\", \"identity\"]], \"passed\": true}, {\"check\": \"member-separator fixture 1\", \"actual\": [[\"Range\", \"bytes=5-\"], [\"If-Range\", \"Mon, 01 Jan 2001 00:00:00 GMT\"]], \"expected\": [[\"Range\", \"bytes=5-\"], [\"If-Range\", \"Mon, 01 Jan 2001 00:00:00 GMT\"]], \"passed\": true}, {\"check\": \"member-separator fixture 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"member-separator fixture 3\", \"actual\": [[\"Range\", \"bytes=9-9,0-0\"]], \"expected\": [[\"Range\", \"bytes=9-9,0-0\"]], \"passed\": true}, {\"check\": \"member-separator fixture 4\", \"actual\": [[\"Range\", \"bytes=-0\"], [\"If-Range\", \"\\\"\\\"\"]], \"expected\": [[\"Range\", \"bytes=-0\"], [\"If-Range\", \"\\\"\\\"\"]], \"passed\": true}, {\"check\": \"member-separator fixture 5\", \"actual\": [[\"Accept-Encoding\", \"identity\"]], \"expected\": [[\"Accept-Encoding\", \"identity\"]], \"passed\": true}, {\"check\": \"member-separator fixture 6\", \"actual\": [[\"Range\", \"bytes=0-\"]], \"expected\": [[\"Range\", \"bytes=0-\"]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}