FA-30851 / Keyboard interactions / Open access

Physical press ownership registry: Repeated down events are counted as additional physical presses · case 01

The event trace violates the repeat accounting rule and produces incorrect keyboard state or command output.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Repeated down events are counted as additional physical presses.

THE FAILURE

Repeated down events are counted as additional physical presses.

Unsuccessful approach: The partial repair changes this transition to if not fresh: presses+=1, which still violates the model contract on the explicit regression traces.

Case contract

Events are [kind,device,code,location]. Down inserts a unique physical token; up removes exactly that token; disconnect clears that device; blur clears all. Track maximum simultaneous held count, accepted presses, releases, orphan ups and sorted held tokens. Inputs are finite ordered event traces; return the stated deterministic state. Batch entries are independent. N varies the number of independent input transactions.

Why this case matters

Controlled keyboard event processing model for debugging application event logic.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(cases):
    def run(c):
        held=set(); peak=0; presses=0; releases=0; orphan=0
        for kind,device,code,location in c:
            token=(device,code,location)
            if kind=='down':
                fresh=token not in held
                presses+=1
                held.add(token)
                peak=max(peak,len(held))
            elif kind=='up':
                if token in held:
                    held.remove(token)
                    releases+=1
                else: orphan+=1
            elif kind=='disconnect':
                held={x for x in held if x[0]!=device}
            elif kind=='blur':
                held.clear()
        return [sorted([list(x) for x in held]),peak,presses,releases,orphan]
    return [run(c) for c in cases]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('physical-registry scenario 0', solve([[]] * N), [[[], 0, 0, 0, 0]] * N)
check('physical-registry scenario 1', solve([[['up', 'a', 'A', 0], ['up', 'a', 'B', 0]]] * N), [[[], 0, 0, 0, 2]] * N)
check('physical-registry scenario 2', solve([[['down', 'a', 'A', 0], ['down', 'a', 'A', 0], ['down', 'a', 'A', 0]]] * N), [[[['a', 'A', 0]], 1, 1, 0, 0]] * N)
check('physical-registry scenario 3', solve([[['down', 'a', 'A', 0], ['down', 'b', 'A', 0], ['up', 'a', 'A', 0]]] * N), [[[['b', 'A', 0]], 2, 2, 1, 0]] * N)
check('physical-registry scenario 4', solve([[['down', 'a', 'S', 1], ['down', 'a', 'S', 3], ['up', 'a', 'S', 1]]] * N), [[[['a', 'S', 3]], 2, 2, 1, 0]] * N)
check('physical-registry scenario 5', solve([[['down', 'a', 'A', 0], ['down', 'a', 'B', 0], ['up', 'a', 'A', 0], ['down', 'a', 'C', 0], ['up', 'a', 'B', 0], ['up', 'a', 'C', 0], ['down', 'a', 'D', 0]]] * N), [[[['a', 'D', 0]], 2, 4, 3, 0]] * N)
check('physical-registry scenario 6', solve([[['down', 'a', 'A', 0], ['down', 'b', 'B', 0], ['disconnect', 'a', '', 0]]] * N), [[[['b', 'B', 0]], 2, 2, 0, 0]] * N)
check('physical-registry scenario 7', solve([[['down', 'a', 'A', 0], ['down', 'a', 'B', 1], ['blur', '', '', 0]]] * N), [[[], 2, 2, 0, 0]] * 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
physical-registry scenario 0	`[[[], 0, 0, 0, 0]]`	`[[[], 0, 0, 0, 0]]`	Passed
physical-registry scenario 1	`[[[], 0, 0, 0, 2]]`	`[[[], 0, 0, 0, 2]]`	Passed
physical-registry scenario 2	`[[[['a', 'A', 0]], 1, 3, 0, 0]]`	`[[[['a', 'A', 0]], 1, 1, 0, 0]]`	Failed
physical-registry scenario 3	`[[[['b', 'A', 0]], 2, 2, 1, 0]]`	`[[[['b', 'A', 0]], 2, 2, 1, 0]]`	Passed
physical-registry scenario 4	`[[[['a', 'S', 3]], 2, 2, 1, 0]]`	`[[[['a', 'S', 3]], 2, 2, 1, 0]]`	Passed
physical-registry scenario 5	`[[[['a', 'D', 0]], 2, 4, 3, 0]]`	`[[[['a', 'D', 0]], 2, 4, 3, 0]]`	Passed
physical-registry scenario 6	`[[[['b', 'B', 0]], 2, 2, 0, 0]]`	`[[[['b', 'B', 0]], 2, 2, 0, 0]]`	Passed
physical-registry scenario 7	`[[[], 2, 2, 0, 0]]`	`[[[], 2, 2, 0, 0]]`	Passed

SHA-256 / 4b2fd93cdd1eafe5781fdde9078ae92696e8309f29d38f5ea49410b738fe1248

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(cases):
    def run(c):
        held=set(); peak=0; presses=0; releases=0; orphan=0
        for kind,device,code,location in c:
            token=(device,code,location)
            if kind=='down':
                fresh=token not in held
                if not fresh: presses+=1
                held.add(token)
                peak=max(peak,len(held))
            elif kind=='up':
                if token in held:
                    held.remove(token)
                    releases+=1
                else: orphan+=1
            elif kind=='disconnect':
                held={x for x in held if x[0]!=device}
            elif kind=='blur':
                held.clear()
        return [sorted([list(x) for x in held]),peak,presses,releases,orphan]
    return [run(c) for c in cases]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('physical-registry scenario 0', solve([[]] * N), [[[], 0, 0, 0, 0]] * N)
check('physical-registry scenario 1', solve([[['up', 'a', 'A', 0], ['up', 'a', 'B', 0]]] * N), [[[], 0, 0, 0, 2]] * N)
check('physical-registry scenario 2', solve([[['down', 'a', 'A', 0], ['down', 'a', 'A', 0], ['down', 'a', 'A', 0]]] * N), [[[['a', 'A', 0]], 1, 1, 0, 0]] * N)
check('physical-registry scenario 3', solve([[['down', 'a', 'A', 0], ['down', 'b', 'A', 0], ['up', 'a', 'A', 0]]] * N), [[[['b', 'A', 0]], 2, 2, 1, 0]] * N)
check('physical-registry scenario 4', solve([[['down', 'a', 'S', 1], ['down', 'a', 'S', 3], ['up', 'a', 'S', 1]]] * N), [[[['a', 'S', 3]], 2, 2, 1, 0]] * N)
check('physical-registry scenario 5', solve([[['down', 'a', 'A', 0], ['down', 'a', 'B', 0], ['up', 'a', 'A', 0], ['down', 'a', 'C', 0], ['up', 'a', 'B', 0], ['up', 'a', 'C', 0], ['down', 'a', 'D', 0]]] * N), [[[['a', 'D', 0]], 2, 4, 3, 0]] * N)
check('physical-registry scenario 6', solve([[['down', 'a', 'A', 0], ['down', 'b', 'B', 0], ['disconnect', 'a', '', 0]]] * N), [[[['b', 'B', 0]], 2, 2, 0, 0]] * N)
check('physical-registry scenario 7', solve([[['down', 'a', 'A', 0], ['down', 'a', 'B', 1], ['blur', '', '', 0]]] * N), [[[], 2, 2, 0, 0]] * 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
physical-registry scenario 0	`[[[], 0, 0, 0, 0]]`	`[[[], 0, 0, 0, 0]]`	Passed
physical-registry scenario 1	`[[[], 0, 0, 0, 2]]`	`[[[], 0, 0, 0, 2]]`	Passed
physical-registry scenario 2	`[[[['a', 'A', 0]], 1, 2, 0, 0]]`	`[[[['a', 'A', 0]], 1, 1, 0, 0]]`	Failed
physical-registry scenario 3	`[[[['b', 'A', 0]], 2, 0, 1, 0]]`	`[[[['b', 'A', 0]], 2, 2, 1, 0]]`	Failed
physical-registry scenario 4	`[[[['a', 'S', 3]], 2, 0, 1, 0]]`	`[[[['a', 'S', 3]], 2, 2, 1, 0]]`	Failed
physical-registry scenario 5	`[[[['a', 'D', 0]], 2, 0, 3, 0]]`	`[[[['a', 'D', 0]], 2, 4, 3, 0]]`	Failed
physical-registry scenario 6	`[[[['b', 'B', 0]], 2, 0, 0, 0]]`	`[[[['b', 'B', 0]], 2, 2, 0, 0]]`	Failed
physical-registry scenario 7	`[[[], 2, 0, 0, 0]]`	`[[[], 2, 2, 0, 0]]`	Failed

SHA-256 / befdba5d997528817ba7622a0513b9542571b6861135eaebe8b9247be07ec95d

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

Member access is invitation-based. Sign in with your invited account to inspect the repair.

Verification & scope

Offline stipulated event model, not a browser implementation or web standard conformance claim. 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 2026-09-29T14:41:57.018695+00:00.

Case digest / 0b639383a9c06e93a9bbc8595ff755333d368bff0e0b1af501206f82d0ab7b60