FA-26351 / HTTP ranges / Open access
Wildcard preconditions test representation existence without requiring a stored tag · case 01
Wildcard preconditions test representation existence without requiring a stored tag.
ROOT CAUSE
The if-match-wildcard-existence decision uses return [200,body] if tag else [412,""].
VERIFIED REPAIR
Apply the bounded decision exactly: return [200,body] if exists else [412,""]
Unsuccessful approach: The partial repair uses return [200,body] if exists and tag is not None else [412,""], which still violates the stated contract.
Case contract
For an If-Match wildcard, return [200,body] for any existing representation, including an untagged one, else [412,empty].
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(exists, tag, body):
return [200,body] if tag else [412,""]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('if-match-wildcard-existence fixture 0', solve(True,None,"x"*N), [200,"x"*N])
check('if-match-wildcard-existence fixture 1', solve(True,"","x"*N), [200,"x"*N])
check('if-match-wildcard-existence fixture 2', solve(False,"old","x"*N), [412,""])
check('if-match-wildcard-existence fixture 3', solve(False,None,""), [412,""])
check('if-match-wildcard-existence fixture 4', solve(True,"v", ""), [200,""])
check('if-match-wildcard-existence fixture 5', solve(True,"v","z"*N), [200,"z"*N])
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| if-match-wildcard-existence fixture 0 | [412, ''] | [200, 'x'] | Failed |
| if-match-wildcard-existence fixture 1 | [412, ''] | [200, 'x'] | Failed |
| if-match-wildcard-existence fixture 2 | [200, 'x'] | [412, ''] | Failed |
| if-match-wildcard-existence fixture 3 | [412, ''] | [412, ''] | Passed |
| if-match-wildcard-existence fixture 4 | [200, ''] | [200, ''] | Passed |
| if-match-wildcard-existence fixture 5 | [200, 'z'] | [200, 'z'] | Passed |
SHA-256 / 4e99842e56e5bc8f22f1cdfe04fa5bbcf8ee47c15c50c0aaa89ef423aa25db69
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(exists, tag, body):
return [200,body] if exists and tag is not None else [412,""]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('if-match-wildcard-existence fixture 0', solve(True,None,"x"*N), [200,"x"*N])
check('if-match-wildcard-existence fixture 1', solve(True,"","x"*N), [200,"x"*N])
check('if-match-wildcard-existence fixture 2', solve(False,"old","x"*N), [412,""])
check('if-match-wildcard-existence fixture 3', solve(False,None,""), [412,""])
check('if-match-wildcard-existence fixture 4', solve(True,"v", ""), [200,""])
check('if-match-wildcard-existence fixture 5', solve(True,"v","z"*N), [200,"z"*N])
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| if-match-wildcard-existence fixture 0 | [412, ''] | [200, 'x'] | Failed |
| if-match-wildcard-existence fixture 1 | [200, 'x'] | [200, 'x'] | Passed |
| if-match-wildcard-existence fixture 2 | [412, ''] | [412, ''] | Passed |
| if-match-wildcard-existence fixture 3 | [412, ''] | [412, ''] | Passed |
| if-match-wildcard-existence fixture 4 | [200, ''] | [200, ''] | Passed |
| if-match-wildcard-existence fixture 5 | [200, 'z'] | [200, 'z'] | Passed |
SHA-256 / 429c699f134b05c1c9a64c7f9be4d0d80bdd0f192663129bdf0a68a700ce0dd1
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
N = 1
observations = []
def solve(exists, tag, body):
return [200,body] if exists else [412,""]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('if-match-wildcard-existence fixture 0', solve(True,None,"x"*N), [200,"x"*N])
check('if-match-wildcard-existence fixture 1', solve(True,"","x"*N), [200,"x"*N])
check('if-match-wildcard-existence fixture 2', solve(False,"old","x"*N), [412,""])
check('if-match-wildcard-existence fixture 3', solve(False,None,""), [412,""])
check('if-match-wildcard-existence fixture 4', solve(True,"v", ""), [200,""])
check('if-match-wildcard-existence fixture 5', solve(True,"v","z"*N), [200,"z"*N])
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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| if-match-wildcard-existence fixture 0 | [200, 'x'] | [200, 'x'] | Passed |
| if-match-wildcard-existence fixture 1 | [200, 'x'] | [200, 'x'] | Passed |
| if-match-wildcard-existence fixture 2 | [412, ''] | [412, ''] | Passed |
| if-match-wildcard-existence fixture 3 | [412, ''] | [412, ''] | Passed |
| if-match-wildcard-existence fixture 4 | [200, ''] | [200, ''] | Passed |
| if-match-wildcard-existence fixture 5 | [200, 'z'] | [200, 'z'] | Passed |
SHA-256 / 2b46071166ccf50ac09992de129e51f2cca5094f5f101fa54eb2fe23aec1b450
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 2026-09-29T14:41:15.219634+00:00.
Case digest / 217204980fbe9e1043b0426f45155f6db52a3d7e2c98b8771ad7b0924ef62c1f