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FA-27701 / HTTP ranges / Open access

A remote archive reader locates the central directory from a suffix range response: only a directory starting inside the tail is served locally · case 01

A remote archive reader locates the central directory from a suffix range response: only a directory starting inside the tail is served locally.

Verified by executionVariant 1 · 16 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The remote-zip-directory-directory-in-tail decision uses import struct T=x['total'] want=min(T,x['suffix']) head='bytes=-%d'%want if want>0 else None data=bytes.fromhex(x['tail']) base=T-len(data) p=len(data)-22 while p>=0: if data[p:p+4]==b'PK\x05\x06' and p+22+int.from_bytes(data[p+20:p+22],'little')==len(data): break p-=1 if p<0: return [head,None] disk,cddisk,n1,n2,size,off=struct.unpack_from('<HHHHII',data,p+4) if disk!=0 or cddisk!=0 or n1!=n2: return [head,None] eocd=base+p if off+size>eocd: return [head,None] if off>base: return [head,['local',off-base,size]] return [head,['fetch','bytes=%d-%d'%(off,min(base,off+size)-1)]].

VERIFIED REPAIR

Apply the bounded decision exactly: import struct T=x['total'] want=min(T,x['suffix']) head='bytes=-%d'%want if want>0 else None data=bytes.fromhex(x['tail']) base=T-len(data) p=len(data)-22 while p>=0: if data[p:p+4]==b'PK\x05\x06' and p+22+int.from_bytes(data[p+20:p+22],'little')==len(data): break p-=1 if p<0: return [head,None] disk,cddisk,n1,n2,size,off=struct.unpack_from('<HHHHII',data,p+4) if disk!=0 or cddisk!=0 or n1!=n2: return [head,None] eocd=base+p if off+size>eocd: return [head,None] if off>=base: return [head,['local',off-base,size]] return [head,['fetch','bytes=%d-%d'%(off,min(base,off+size)-1)]]

Unsuccessful approach: The partial repair uses import struct T=x['total'] want=min(T,x['suffix']) head='bytes=-%d'%want if want>0 else None data=bytes.fromhex(x['tail']) base=T-len(data) p=len(data)-22 while p>=0: if data[p:p+4]==b'PK\x05\x06' and p+22+int.from_bytes(data[p+20:p+22],'little')==len(data): break p-=1 if p<0: return [head,None] disk,cddisk,n1,n2,size,off=struct.unpack_from('<HHHHII',data,p+4) if disk!=0 or cddisk!=0 or n1!=n2: return [head,None] eocd=base+p if off+size>eocd: return [head,None] if off+size>=base: return [head,['local',off-base,size]] return [head,['fetch','bytes=%d-%d'%(off,min(base,off+size)-1)]], which still violates the stated contract.

Case contract

x has total representation length, requested suffix length and the hex bytes of the suffix response (the last min(total,suffix) bytes). Emit the suffix Range value (null when it would be zero bytes). Scan backward for the end record signature PK\x05\x06 whose little-endian comment length makes the 22-byte record plus comment end exactly at the tail end. Reject multi-disk archives (disk or directory disk nonzero, or differing entry counts) and a directory that extends past the end record. A directory starting inside the tail is ["local",tail-index,size]; otherwise request only the missing prefix before the tail as ["fetch",inclusive range]. Output [suffix-range,plan-or-null].

Why this case matters

Range responses combine representation identity, conditional requests, framing, and partial-object state.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    import struct
    T=x['total']
    want=min(T,x['suffix'])
    head='bytes=-%d'%want if want>0 else None
    data=bytes.fromhex(x['tail'])
    base=T-len(data)
    p=len(data)-22
    while p>=0:
        if data[p:p+4]==b'PK\x05\x06' and p+22+int.from_bytes(data[p+20:p+22],'little')==len(data): break
        p-=1
    if p<0: return [head,None]
    disk,cddisk,n1,n2,size,off=struct.unpack_from('<HHHHII',data,p+4)
    if disk!=0 or cddisk!=0 or n1!=n2: return [head,None]
    eocd=base+p
    if off+size>eocd: return [head,None]
    if off>base: return [head,['local',off-base,size]]
    return [head,['fetch','bytes=%d-%d'%(off,min(base,off+size)-1)]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('directory-in-tail fixture 0', json.loads(json.dumps(solve({'suffix':64,'tail':'0101010101010101010101010101010101010101434343434343434343434343434343434343504b0506000000000100010012000000140000000000','total':60}))), json.loads(json.dumps(['bytes=-60',['local',20,18]])))
check('directory-in-tail fixture 1', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000000000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',['local',0,18]])))
check('directory-in-tail fixture 2', json.loads(json.dumps(solve({'suffix':50,'tail':'43434343434343434343434343434343434300000000000000000000504b0506000000000100010012000000b60300000000','total':1000}))), json.loads(json.dumps(['bytes=-50',['local',0,18]])))
check('directory-in-tail fixture 3', json.loads(json.dumps(solve({'suffix':30,'tail':'4343434343434343504b0506000000000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-30',['fetch','bytes=960-969']])))
check('directory-in-tail fixture 4', json.loads(json.dumps(solve({'suffix':22,'tail':'504b050600000000010001004e000000840300000000','total':1000}))), json.loads(json.dumps(['bytes=-22',['fetch','bytes=900-977']])))
check('directory-in-tail fixture 5', json.loads(json.dumps(solve({'suffix':25,'tail':'504b050600000000010001004b000000840300000300616263','total':1000}))), json.loads(json.dumps(['bytes=-25',['fetch','bytes=900-974']])))
check('directory-in-tail fixture 6', json.loads(json.dumps(solve({'suffix':80,'tail':'434343434343434343434343434343434343504b0506000000000100010012000000880000001800504b05060000000001000100000000000000000000007a7a','total':200}))), json.loads(json.dumps(['bytes=-80',['local',0,18]])))
check('directory-in-tail fixture 7', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000001000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 8', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506010001000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 9', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000000000100020012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 10', json.loads(json.dumps(solve({'suffix':100,'tail':'02020202020202020202020202020202020202020202020202020202020202020202020202020202504b05060000000001000100140000001e0000000000','total':62}))), json.loads(json.dumps(['bytes=-62',None])))
check('directory-in-tail fixture 11', json.loads(json.dumps(solve({'suffix':30,'tail':'030303030303030303030303030303030303030303030303030303030303','total':30}))), json.loads(json.dumps(['bytes=-30',None])))
check('directory-in-tail fixture 12', json.loads(json.dumps(solve({'suffix':30,'tail':'000000000000000000000000000000000000000000000000000000000000','total':30}))), json.loads(json.dumps(['bytes=-30',None])))
check('directory-in-tail fixture 13', json.loads(json.dumps(solve({'suffix':64,'tail':'','total':0}))), json.loads(json.dumps([None,None])))
check('directory-in-tail fixture 14', json.loads(json.dumps(solve({'suffix':64,'tail':'504b0506000000000000000000000000000000000000','total':22}))), json.loads(json.dumps(['bytes=-22',['local',0,0]])))
check('directory-in-tail fixture 15', json.loads(json.dumps(solve({'suffix':32+N,'tail':"11"*10+"504b0506"+"00000000"+"01000100"+"0a000000"+(468-N).to_bytes(4,"little").hex()+(N).to_bytes(2,"little").hex()+"63"*N,'total':500}))), json.loads(json.dumps(["bytes=-%d"%(32+N),['local',0,10]])))
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
directory-in-tail fixture 0['bytes=-60', ['local', 20, 18]]['bytes=-60', ['local', 20, 18]]Passed
directory-in-tail fixture 1['bytes=-40', ['fetch', 'bytes=960-959']]['bytes=-40', ['local', 0, 18]]Failed
directory-in-tail fixture 2['bytes=-50', ['fetch', 'bytes=950-949']]['bytes=-50', ['local', 0, 18]]Failed
directory-in-tail fixture 3['bytes=-30', ['fetch', 'bytes=960-969']]['bytes=-30', ['fetch', 'bytes=960-969']]Passed
directory-in-tail fixture 4['bytes=-22', ['fetch', 'bytes=900-977']]['bytes=-22', ['fetch', 'bytes=900-977']]Passed
directory-in-tail fixture 5['bytes=-25', ['fetch', 'bytes=900-974']]['bytes=-25', ['fetch', 'bytes=900-974']]Passed
directory-in-tail fixture 6['bytes=-80', ['fetch', 'bytes=136-135']]['bytes=-80', ['local', 0, 18]]Failed
directory-in-tail fixture 7['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 8['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 9['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 10['bytes=-62', None]['bytes=-62', None]Passed
directory-in-tail fixture 11['bytes=-30', None]['bytes=-30', None]Passed
directory-in-tail fixture 12['bytes=-30', None]['bytes=-30', None]Passed
directory-in-tail fixture 13[None, None][None, None]Passed
directory-in-tail fixture 14['bytes=-22', ['fetch', 'bytes=0--1']]['bytes=-22', ['local', 0, 0]]Failed
directory-in-tail fixture 15['bytes=-33', ['fetch', 'bytes=467-466']]['bytes=-33', ['local', 0, 10]]Failed

SHA-256 / fb394b779b82a42aff2662de278c156b5faa2e8def88156c14bbf54ae95d14a9

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    import struct
    T=x['total']
    want=min(T,x['suffix'])
    head='bytes=-%d'%want if want>0 else None
    data=bytes.fromhex(x['tail'])
    base=T-len(data)
    p=len(data)-22
    while p>=0:
        if data[p:p+4]==b'PK\x05\x06' and p+22+int.from_bytes(data[p+20:p+22],'little')==len(data): break
        p-=1
    if p<0: return [head,None]
    disk,cddisk,n1,n2,size,off=struct.unpack_from('<HHHHII',data,p+4)
    if disk!=0 or cddisk!=0 or n1!=n2: return [head,None]
    eocd=base+p
    if off+size>eocd: return [head,None]
    if off+size>=base: return [head,['local',off-base,size]]
    return [head,['fetch','bytes=%d-%d'%(off,min(base,off+size)-1)]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('directory-in-tail fixture 0', json.loads(json.dumps(solve({'suffix':64,'tail':'0101010101010101010101010101010101010101434343434343434343434343434343434343504b0506000000000100010012000000140000000000','total':60}))), json.loads(json.dumps(['bytes=-60',['local',20,18]])))
check('directory-in-tail fixture 1', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000000000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',['local',0,18]])))
check('directory-in-tail fixture 2', json.loads(json.dumps(solve({'suffix':50,'tail':'43434343434343434343434343434343434300000000000000000000504b0506000000000100010012000000b60300000000','total':1000}))), json.loads(json.dumps(['bytes=-50',['local',0,18]])))
check('directory-in-tail fixture 3', json.loads(json.dumps(solve({'suffix':30,'tail':'4343434343434343504b0506000000000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-30',['fetch','bytes=960-969']])))
check('directory-in-tail fixture 4', json.loads(json.dumps(solve({'suffix':22,'tail':'504b050600000000010001004e000000840300000000','total':1000}))), json.loads(json.dumps(['bytes=-22',['fetch','bytes=900-977']])))
check('directory-in-tail fixture 5', json.loads(json.dumps(solve({'suffix':25,'tail':'504b050600000000010001004b000000840300000300616263','total':1000}))), json.loads(json.dumps(['bytes=-25',['fetch','bytes=900-974']])))
check('directory-in-tail fixture 6', json.loads(json.dumps(solve({'suffix':80,'tail':'434343434343434343434343434343434343504b0506000000000100010012000000880000001800504b05060000000001000100000000000000000000007a7a','total':200}))), json.loads(json.dumps(['bytes=-80',['local',0,18]])))
check('directory-in-tail fixture 7', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000001000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 8', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506010001000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 9', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000000000100020012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 10', json.loads(json.dumps(solve({'suffix':100,'tail':'02020202020202020202020202020202020202020202020202020202020202020202020202020202504b05060000000001000100140000001e0000000000','total':62}))), json.loads(json.dumps(['bytes=-62',None])))
check('directory-in-tail fixture 11', json.loads(json.dumps(solve({'suffix':30,'tail':'030303030303030303030303030303030303030303030303030303030303','total':30}))), json.loads(json.dumps(['bytes=-30',None])))
check('directory-in-tail fixture 12', json.loads(json.dumps(solve({'suffix':30,'tail':'000000000000000000000000000000000000000000000000000000000000','total':30}))), json.loads(json.dumps(['bytes=-30',None])))
check('directory-in-tail fixture 13', json.loads(json.dumps(solve({'suffix':64,'tail':'','total':0}))), json.loads(json.dumps([None,None])))
check('directory-in-tail fixture 14', json.loads(json.dumps(solve({'suffix':64,'tail':'504b0506000000000000000000000000000000000000','total':22}))), json.loads(json.dumps(['bytes=-22',['local',0,0]])))
check('directory-in-tail fixture 15', json.loads(json.dumps(solve({'suffix':32+N,'tail':"11"*10+"504b0506"+"00000000"+"01000100"+"0a000000"+(468-N).to_bytes(4,"little").hex()+(N).to_bytes(2,"little").hex()+"63"*N,'total':500}))), json.loads(json.dumps(["bytes=-%d"%(32+N),['local',0,10]])))
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
directory-in-tail fixture 0['bytes=-60', ['local', 20, 18]]['bytes=-60', ['local', 20, 18]]Passed
directory-in-tail fixture 1['bytes=-40', ['local', 0, 18]]['bytes=-40', ['local', 0, 18]]Passed
directory-in-tail fixture 2['bytes=-50', ['local', 0, 18]]['bytes=-50', ['local', 0, 18]]Passed
directory-in-tail fixture 3['bytes=-30', ['local', -10, 18]]['bytes=-30', ['fetch', 'bytes=960-969']]Failed
directory-in-tail fixture 4['bytes=-22', ['local', -78, 78]]['bytes=-22', ['fetch', 'bytes=900-977']]Failed
directory-in-tail fixture 5['bytes=-25', ['local', -75, 75]]['bytes=-25', ['fetch', 'bytes=900-974']]Failed
directory-in-tail fixture 6['bytes=-80', ['local', 0, 18]]['bytes=-80', ['local', 0, 18]]Passed
directory-in-tail fixture 7['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 8['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 9['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 10['bytes=-62', None]['bytes=-62', None]Passed
directory-in-tail fixture 11['bytes=-30', None]['bytes=-30', None]Passed
directory-in-tail fixture 12['bytes=-30', None]['bytes=-30', None]Passed
directory-in-tail fixture 13[None, None][None, None]Passed
directory-in-tail fixture 14['bytes=-22', ['local', 0, 0]]['bytes=-22', ['local', 0, 0]]Passed
directory-in-tail fixture 15['bytes=-33', ['local', 0, 10]]['bytes=-33', ['local', 0, 10]]Passed

SHA-256 / 63f7f0f346d89bdba45bb7fb0a5b99248ee7ccd547ec48d66a8a67b3bfdcd4c7

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    import struct
    T=x['total']
    want=min(T,x['suffix'])
    head='bytes=-%d'%want if want>0 else None
    data=bytes.fromhex(x['tail'])
    base=T-len(data)
    p=len(data)-22
    while p>=0:
        if data[p:p+4]==b'PK\x05\x06' and p+22+int.from_bytes(data[p+20:p+22],'little')==len(data): break
        p-=1
    if p<0: return [head,None]
    disk,cddisk,n1,n2,size,off=struct.unpack_from('<HHHHII',data,p+4)
    if disk!=0 or cddisk!=0 or n1!=n2: return [head,None]
    eocd=base+p
    if off+size>eocd: return [head,None]
    if off>=base: return [head,['local',off-base,size]]
    return [head,['fetch','bytes=%d-%d'%(off,min(base,off+size)-1)]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('directory-in-tail fixture 0', json.loads(json.dumps(solve({'suffix':64,'tail':'0101010101010101010101010101010101010101434343434343434343434343434343434343504b0506000000000100010012000000140000000000','total':60}))), json.loads(json.dumps(['bytes=-60',['local',20,18]])))
check('directory-in-tail fixture 1', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000000000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',['local',0,18]])))
check('directory-in-tail fixture 2', json.loads(json.dumps(solve({'suffix':50,'tail':'43434343434343434343434343434343434300000000000000000000504b0506000000000100010012000000b60300000000','total':1000}))), json.loads(json.dumps(['bytes=-50',['local',0,18]])))
check('directory-in-tail fixture 3', json.loads(json.dumps(solve({'suffix':30,'tail':'4343434343434343504b0506000000000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-30',['fetch','bytes=960-969']])))
check('directory-in-tail fixture 4', json.loads(json.dumps(solve({'suffix':22,'tail':'504b050600000000010001004e000000840300000000','total':1000}))), json.loads(json.dumps(['bytes=-22',['fetch','bytes=900-977']])))
check('directory-in-tail fixture 5', json.loads(json.dumps(solve({'suffix':25,'tail':'504b050600000000010001004b000000840300000300616263','total':1000}))), json.loads(json.dumps(['bytes=-25',['fetch','bytes=900-974']])))
check('directory-in-tail fixture 6', json.loads(json.dumps(solve({'suffix':80,'tail':'434343434343434343434343434343434343504b0506000000000100010012000000880000001800504b05060000000001000100000000000000000000007a7a','total':200}))), json.loads(json.dumps(['bytes=-80',['local',0,18]])))
check('directory-in-tail fixture 7', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000001000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 8', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506010001000100010012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 9', json.loads(json.dumps(solve({'suffix':40,'tail':'434343434343434343434343434343434343504b0506000000000100020012000000c00300000000','total':1000}))), json.loads(json.dumps(['bytes=-40',None])))
check('directory-in-tail fixture 10', json.loads(json.dumps(solve({'suffix':100,'tail':'02020202020202020202020202020202020202020202020202020202020202020202020202020202504b05060000000001000100140000001e0000000000','total':62}))), json.loads(json.dumps(['bytes=-62',None])))
check('directory-in-tail fixture 11', json.loads(json.dumps(solve({'suffix':30,'tail':'030303030303030303030303030303030303030303030303030303030303','total':30}))), json.loads(json.dumps(['bytes=-30',None])))
check('directory-in-tail fixture 12', json.loads(json.dumps(solve({'suffix':30,'tail':'000000000000000000000000000000000000000000000000000000000000','total':30}))), json.loads(json.dumps(['bytes=-30',None])))
check('directory-in-tail fixture 13', json.loads(json.dumps(solve({'suffix':64,'tail':'','total':0}))), json.loads(json.dumps([None,None])))
check('directory-in-tail fixture 14', json.loads(json.dumps(solve({'suffix':64,'tail':'504b0506000000000000000000000000000000000000','total':22}))), json.loads(json.dumps(['bytes=-22',['local',0,0]])))
check('directory-in-tail fixture 15', json.loads(json.dumps(solve({'suffix':32+N,'tail':"11"*10+"504b0506"+"00000000"+"01000100"+"0a000000"+(468-N).to_bytes(4,"little").hex()+(N).to_bytes(2,"little").hex()+"63"*N,'total':500}))), json.loads(json.dumps(["bytes=-%d"%(32+N),['local',0,10]])))
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
directory-in-tail fixture 0['bytes=-60', ['local', 20, 18]]['bytes=-60', ['local', 20, 18]]Passed
directory-in-tail fixture 1['bytes=-40', ['local', 0, 18]]['bytes=-40', ['local', 0, 18]]Passed
directory-in-tail fixture 2['bytes=-50', ['local', 0, 18]]['bytes=-50', ['local', 0, 18]]Passed
directory-in-tail fixture 3['bytes=-30', ['fetch', 'bytes=960-969']]['bytes=-30', ['fetch', 'bytes=960-969']]Passed
directory-in-tail fixture 4['bytes=-22', ['fetch', 'bytes=900-977']]['bytes=-22', ['fetch', 'bytes=900-977']]Passed
directory-in-tail fixture 5['bytes=-25', ['fetch', 'bytes=900-974']]['bytes=-25', ['fetch', 'bytes=900-974']]Passed
directory-in-tail fixture 6['bytes=-80', ['local', 0, 18]]['bytes=-80', ['local', 0, 18]]Passed
directory-in-tail fixture 7['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 8['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 9['bytes=-40', None]['bytes=-40', None]Passed
directory-in-tail fixture 10['bytes=-62', None]['bytes=-62', None]Passed
directory-in-tail fixture 11['bytes=-30', None]['bytes=-30', None]Passed
directory-in-tail fixture 12['bytes=-30', None]['bytes=-30', None]Passed
directory-in-tail fixture 13[None, None][None, None]Passed
directory-in-tail fixture 14['bytes=-22', ['local', 0, 0]]['bytes=-22', ['local', 0, 0]]Passed
directory-in-tail fixture 15['bytes=-33', ['local', 0, 10]]['bytes=-33', ['local', 0, 10]]Passed

SHA-256 / 63621fd1d5fe5931a6e14c2c4dbd32657f8056bd5577b950fd336b966087480a

Verification & scope

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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:41:27.431827+00:00.

Case digest / 75dc191ff06284a86eec398e78a7f7e5756c9e639d6d3afd61d93e3da3c36f2c