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FA-31781 / Keyboard interactions / Open access

Press-time remapping and logical key reference counts: Logical release drops all owners or fails to release its own reference · case 01

The event trace violates the logical decrement rule and produces incorrect keyboard state or command output.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Logical release drops all owners or fails to release its own reference.

VERIFIED REPAIR

Use the contract transition `counts[logical]=counts.get(logical,0)-1` at the logical decrement fault site; preserve the other state transitions.

Unsuccessful approach: The partial repair changes this transition to counts[logical]=counts.get(logical,0), which still violates the model contract on the explicit regression traces.

Case contract

Events [kind,key,value]. Map replaces future press mapping; None disables output. Down captures current mapping once per physical key. Several physical keys mapping to one logical key share a reference count: emit logical down at 0->1 and up at 1->0. Release uses captured mapping even after remap. Reset emits sorted ups for all logical held keys and clears presses. Return events, captured physical map and logical counts. 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):
        mapping={}; active={}; counts={}; out=[]
        for kind,key,value in c:
            if kind=='map': mapping[key]=value
            elif kind=='down' and key not in active:
                logical=mapping.get(key,key)
                active[key]=logical
                if logical is not None:
                    count=counts.get(logical,0)
                    counts[logical]=count+1
                    if count==0: out.append(['down',logical])
            elif kind=='up' and key in active:
                logical=active.pop(key)
                if logical is not None:
                    counts[logical]=0
                    if counts[logical]==0:
                        out.append(['up',logical])
                        counts.pop(logical,None)
            elif kind=='reset':
                for logical in sorted(counts): out.append(['up',logical])
                active.clear(); counts.clear()
        return [out,sorted([[k,v] for k,v in active.items()]),sorted([[k,v] for k,v in counts.items()])]
    return [run(c) for c in cases]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('remap-release-ownership scenario 0', solve([[]] * N), [[[], [], []]] * N)
check('remap-release-ownership scenario 1', solve([[['down', 'A', None], ['up', 'A', None]]] * N), [[[['down', 'A'], ['up', 'A']], [], []]] * N)
check('remap-release-ownership scenario 2', solve([[['map', 'A', 'X'], ['map', 'A', 'Y'], ['down', 'A', None]]] * N), [[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]] * N)
check('remap-release-ownership scenario 3', solve([[['map', 'A', 'X'], ['down', 'A', None], ['map', 'A', 'Y'], ['up', 'A', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * N)
check('remap-release-ownership scenario 4', solve([[['map', 'A', 'X'], ['map', 'B', 'X'], ['down', 'A', None], ['down', 'B', None], ['up', 'A', None]]] * N), [[[['down', 'X']], [['B', 'X']], [['X', 1]]]] * N)
check('remap-release-ownership scenario 5', solve([[['map', 'A', 'X'], ['down', 'A', None], ['down', 'A', None], ['up', 'A', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * N)
check('remap-release-ownership scenario 6', solve([[['map', 'A', None], ['down', 'A', None]]] * N), [[[], [['A', None]], []]] * N)
check('remap-release-ownership scenario 7', solve([[['map', 'A', ''], ['down', 'A', None]]] * N), [[[['down', '']], [['A', '']], [['', 1]]]] * N)
check('remap-release-ownership scenario 8', solve([[['map', 'A', 'X'], ['down', 'A', None], ['reset', '', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * 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 fixtureActualExpectedOutcome
remap-release-ownership scenario 0[[[], [], []]][[[], [], []]]Passed
remap-release-ownership scenario 1[[[['down', 'A'], ['up', 'A']], [], []]][[[['down', 'A'], ['up', 'A']], [], []]]Passed
remap-release-ownership scenario 2[[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]][[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]]Passed
remap-release-ownership scenario 3[[[['down', 'X'], ['up', 'X']], [], []]][[[['down', 'X'], ['up', 'X']], [], []]]Passed
remap-release-ownership scenario 4[[[['down', 'X'], ['up', 'X']], [['B', 'X']], []]][[[['down', 'X']], [['B', 'X']], [['X', 1]]]]Failed
remap-release-ownership scenario 5[[[['down', 'X'], ['up', 'X']], [], []]][[[['down', 'X'], ['up', 'X']], [], []]]Passed
remap-release-ownership scenario 6[[[], [['A', None]], []]][[[], [['A', None]], []]]Passed
remap-release-ownership scenario 7[[[['down', '']], [['A', '']], [['', 1]]]][[[['down', '']], [['A', '']], [['', 1]]]]Passed
remap-release-ownership scenario 8[[[['down', 'X'], ['up', 'X']], [], []]][[[['down', 'X'], ['up', 'X']], [], []]]Passed

SHA-256 / f660991c19e78132e37d54cde82611a73dfc0a8379f7fc0fc03f40a9bfb98663

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):
        mapping={}; active={}; counts={}; out=[]
        for kind,key,value in c:
            if kind=='map': mapping[key]=value
            elif kind=='down' and key not in active:
                logical=mapping.get(key,key)
                active[key]=logical
                if logical is not None:
                    count=counts.get(logical,0)
                    counts[logical]=count+1
                    if count==0: out.append(['down',logical])
            elif kind=='up' and key in active:
                logical=active.pop(key)
                if logical is not None:
                    counts[logical]=counts.get(logical,0)
                    if counts[logical]==0:
                        out.append(['up',logical])
                        counts.pop(logical,None)
            elif kind=='reset':
                for logical in sorted(counts): out.append(['up',logical])
                active.clear(); counts.clear()
        return [out,sorted([[k,v] for k,v in active.items()]),sorted([[k,v] for k,v in counts.items()])]
    return [run(c) for c in cases]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('remap-release-ownership scenario 0', solve([[]] * N), [[[], [], []]] * N)
check('remap-release-ownership scenario 1', solve([[['down', 'A', None], ['up', 'A', None]]] * N), [[[['down', 'A'], ['up', 'A']], [], []]] * N)
check('remap-release-ownership scenario 2', solve([[['map', 'A', 'X'], ['map', 'A', 'Y'], ['down', 'A', None]]] * N), [[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]] * N)
check('remap-release-ownership scenario 3', solve([[['map', 'A', 'X'], ['down', 'A', None], ['map', 'A', 'Y'], ['up', 'A', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * N)
check('remap-release-ownership scenario 4', solve([[['map', 'A', 'X'], ['map', 'B', 'X'], ['down', 'A', None], ['down', 'B', None], ['up', 'A', None]]] * N), [[[['down', 'X']], [['B', 'X']], [['X', 1]]]] * N)
check('remap-release-ownership scenario 5', solve([[['map', 'A', 'X'], ['down', 'A', None], ['down', 'A', None], ['up', 'A', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * N)
check('remap-release-ownership scenario 6', solve([[['map', 'A', None], ['down', 'A', None]]] * N), [[[], [['A', None]], []]] * N)
check('remap-release-ownership scenario 7', solve([[['map', 'A', ''], ['down', 'A', None]]] * N), [[[['down', '']], [['A', '']], [['', 1]]]] * N)
check('remap-release-ownership scenario 8', solve([[['map', 'A', 'X'], ['down', 'A', None], ['reset', '', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * 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 fixtureActualExpectedOutcome
remap-release-ownership scenario 0[[[], [], []]][[[], [], []]]Passed
remap-release-ownership scenario 1[[[['down', 'A']], [], [['A', 1]]]][[[['down', 'A'], ['up', 'A']], [], []]]Failed
remap-release-ownership scenario 2[[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]][[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]]Passed
remap-release-ownership scenario 3[[[['down', 'X']], [], [['X', 1]]]][[[['down', 'X'], ['up', 'X']], [], []]]Failed
remap-release-ownership scenario 4[[[['down', 'X']], [['B', 'X']], [['X', 2]]]][[[['down', 'X']], [['B', 'X']], [['X', 1]]]]Failed
remap-release-ownership scenario 5[[[['down', 'X']], [], [['X', 1]]]][[[['down', 'X'], ['up', 'X']], [], []]]Failed
remap-release-ownership scenario 6[[[], [['A', None]], []]][[[], [['A', None]], []]]Passed
remap-release-ownership scenario 7[[[['down', '']], [['A', '']], [['', 1]]]][[[['down', '']], [['A', '']], [['', 1]]]]Passed
remap-release-ownership scenario 8[[[['down', 'X'], ['up', 'X']], [], []]][[[['down', 'X'], ['up', 'X']], [], []]]Passed

SHA-256 / 216d8ae4effb5a9e4e1b3d5cb15f963c1207f57e887d890921c7f8b41d901ba4

3 / The verified repair

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

N = 1
observations = []
def solve(cases):
    def run(c):
        mapping={}; active={}; counts={}; out=[]
        for kind,key,value in c:
            if kind=='map': mapping[key]=value
            elif kind=='down' and key not in active:
                logical=mapping.get(key,key)
                active[key]=logical
                if logical is not None:
                    count=counts.get(logical,0)
                    counts[logical]=count+1
                    if count==0: out.append(['down',logical])
            elif kind=='up' and key in active:
                logical=active.pop(key)
                if logical is not None:
                    counts[logical]=counts.get(logical,0)-1
                    if counts[logical]==0:
                        out.append(['up',logical])
                        counts.pop(logical,None)
            elif kind=='reset':
                for logical in sorted(counts): out.append(['up',logical])
                active.clear(); counts.clear()
        return [out,sorted([[k,v] for k,v in active.items()]),sorted([[k,v] for k,v in counts.items()])]
    return [run(c) for c in cases]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('remap-release-ownership scenario 0', solve([[]] * N), [[[], [], []]] * N)
check('remap-release-ownership scenario 1', solve([[['down', 'A', None], ['up', 'A', None]]] * N), [[[['down', 'A'], ['up', 'A']], [], []]] * N)
check('remap-release-ownership scenario 2', solve([[['map', 'A', 'X'], ['map', 'A', 'Y'], ['down', 'A', None]]] * N), [[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]] * N)
check('remap-release-ownership scenario 3', solve([[['map', 'A', 'X'], ['down', 'A', None], ['map', 'A', 'Y'], ['up', 'A', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * N)
check('remap-release-ownership scenario 4', solve([[['map', 'A', 'X'], ['map', 'B', 'X'], ['down', 'A', None], ['down', 'B', None], ['up', 'A', None]]] * N), [[[['down', 'X']], [['B', 'X']], [['X', 1]]]] * N)
check('remap-release-ownership scenario 5', solve([[['map', 'A', 'X'], ['down', 'A', None], ['down', 'A', None], ['up', 'A', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * N)
check('remap-release-ownership scenario 6', solve([[['map', 'A', None], ['down', 'A', None]]] * N), [[[], [['A', None]], []]] * N)
check('remap-release-ownership scenario 7', solve([[['map', 'A', ''], ['down', 'A', None]]] * N), [[[['down', '']], [['A', '']], [['', 1]]]] * N)
check('remap-release-ownership scenario 8', solve([[['map', 'A', 'X'], ['down', 'A', None], ['reset', '', None]]] * N), [[[['down', 'X'], ['up', 'X']], [], []]] * 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 fixtureActualExpectedOutcome
remap-release-ownership scenario 0[[[], [], []]][[[], [], []]]Passed
remap-release-ownership scenario 1[[[['down', 'A'], ['up', 'A']], [], []]][[[['down', 'A'], ['up', 'A']], [], []]]Passed
remap-release-ownership scenario 2[[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]][[[['down', 'Y']], [['A', 'Y']], [['Y', 1]]]]Passed
remap-release-ownership scenario 3[[[['down', 'X'], ['up', 'X']], [], []]][[[['down', 'X'], ['up', 'X']], [], []]]Passed
remap-release-ownership scenario 4[[[['down', 'X']], [['B', 'X']], [['X', 1]]]][[[['down', 'X']], [['B', 'X']], [['X', 1]]]]Passed
remap-release-ownership scenario 5[[[['down', 'X'], ['up', 'X']], [], []]][[[['down', 'X'], ['up', 'X']], [], []]]Passed
remap-release-ownership scenario 6[[[], [['A', None]], []]][[[], [['A', None]], []]]Passed
remap-release-ownership scenario 7[[[['down', '']], [['A', '']], [['', 1]]]][[[['down', '']], [['A', '']], [['', 1]]]]Passed
remap-release-ownership scenario 8[[[['down', 'X'], ['up', 'X']], [], []]][[[['down', 'X'], ['up', 'X']], [], []]]Passed

SHA-256 / 68a0d3838c21544769255c0f94b8dc6963c760e29884585c856259d22e91cc48

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 2026-09-29T14:42:05.534758+00:00.

Case digest / becb9e4d8d5a4c5aaa61608003860ccb42131276d23f5d0f1ebb8b55b429851b