{"abstract":"Removed semantic properties remain as explicit nulls.","category":"Accessibility interaction semantics","checks":6,"contract":"Input [initial,revision,updates]. Updates [base_revision,next_revision,changes] apply atomically only if base matches current and next is greater; updates cannot change immutable id or role. Allowed dynamic keys name,description,value,help,language; unknown keys reject whole update. None deletes a property, empty string is retained; values must be strings or None. Return [state,revision,accepted_flags]. Copy initial. Revision advances even for no-op changes.","contract_signature":"data","evaluation_group":"s3-accessibility-property-patch","failed_approach":"The local repair substitutes if value is None: state[key] = '' but still mishandles the regression fixtures.","family":"s3-accessibility-property-patch-deletion-vs-null","id":"FA-53986","implementations":{"attempt":{"sha256":"2fb05669cea792b9ca3d11ab006f4f992c05ed0b12b719180bb862192cc157de","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(data):\n    initial,revision,updates = data\n    state = dict(initial)\n    accepted = []\n    for base,nxt,changes in updates:\n        valid = base == revision and nxt > base\n        valid = valid and all(k in {'name','description','value','help','language'} for k in changes)\n        valid = valid and all(v is None or isinstance(v,str) for v in changes.values())\n        accepted.append(valid)\n        if not valid: continue\n        for key,value in changes.items():\n            if value is None: state[key] = ''\n            else: state[key] = value\n        revision = nxt\n    return [state,revision,accepted]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('contract fixture 1', solve([{'id':'x','role':'image','name':'old'},N,[[N,N+1,{'name':'new','help':''}],[N,N+2,{'name':'stale'}]]],), [{'id':'x','role':'image','name':'new','help':''},N+1,[True,False]])\ncheck('contract fixture 2', solve([{'name':'x','help':'h'},N,[[N,N+1,{'name':None}],[N+1,N+2,{'absent':'bad','help':'bad'}]]],), [{'help':'h'},N+1,[True,False]])\ncheck('contract fixture 3', solve([{'id':'x','role':'image'},N,[[N,N+1,{'id':'y'}],[N,N+1,{'role':'button'}]]],), [{'id':'x','role':'image'},N,[False,False]])\ncheck('contract fixture 4', solve([{},N,[[N,N,{'name':'bad'}],[N,N-1,{}],[N,N+1,{}]]],), [{},N+1,[False,False,True]])\ncheck('contract fixture 5', solve([{'name':'x'},N,[[N,N+1,{'name':42,'help':'partial'}]]],), [{'name':'x'},N,[False]])\ncheck('contract fixture 6', solve([{},N,[[N,N+1,{'name':None,'description':'D','value':'0','language':'en'}]]],), [{'description':'D','value':'0','language':'en'},N+1,[True]])\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":"cc4a345f07f9436f2563153496e30a68d12f4788f3516ed1e26d399e7181c70b","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(data):\n    initial,revision,updates = data\n    state = dict(initial)\n    accepted = []\n    for base,nxt,changes in updates:\n        valid = base == revision and nxt > base\n        valid = valid and all(k in {'name','description','value','help','language'} for k in changes)\n        valid = valid and all(v is None or isinstance(v,str) for v in changes.values())\n        accepted.append(valid)\n        if not valid: continue\n        for key,value in changes.items():\n            if value is None: state[key] = None\n            else: state[key] = value\n        revision = nxt\n    return [state,revision,accepted]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('contract fixture 1', solve([{'id':'x','role':'image','name':'old'},N,[[N,N+1,{'name':'new','help':''}],[N,N+2,{'name':'stale'}]]],), [{'id':'x','role':'image','name':'new','help':''},N+1,[True,False]])\ncheck('contract fixture 2', solve([{'name':'x','help':'h'},N,[[N,N+1,{'name':None}],[N+1,N+2,{'absent':'bad','help':'bad'}]]],), [{'help':'h'},N+1,[True,False]])\ncheck('contract fixture 3', solve([{'id':'x','role':'image'},N,[[N,N+1,{'id':'y'}],[N,N+1,{'role':'button'}]]],), [{'id':'x','role':'image'},N,[False,False]])\ncheck('contract fixture 4', solve([{},N,[[N,N,{'name':'bad'}],[N,N-1,{}],[N,N+1,{}]]],), [{},N+1,[False,False,True]])\ncheck('contract fixture 5', solve([{'name':'x'},N,[[N,N+1,{'name':42,'help':'partial'}]]],), [{'name':'x'},N,[False]])\ncheck('contract fixture 6', solve([{},N,[[N,N+1,{'name':None,'description':'D','value':'0','language':'en'}]]],), [{'description':'D','value':'0','language':'en'},N+1,[True]])\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":"Stipulated finite adapter contract, not a claim of platform accessibility or ARIA conformance. 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-accessibility-property-patch-deletion-vs-null","generated_at":"2026-09-29T14:45:44.317336+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline accessibility bridge model with explicit policy; useful for testing semantic API adapters independently of browser implementations.","root_cause":"The deletion vs null decision in the property patch adapter violates its declared contract.","sha256":"b757d143773a2aaf8d2b7f6efd3b14167fb7cd00ff48adc9071ae408bd184570","title":"Removed semantic properties remain as explicit nulls · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":39.059,"exit_code":1,"observations":[{"actual":[{"help":"","id":"x","name":"new","role":"image"},2,[true,false]],"check":"contract fixture 1","expected":[{"help":"","id":"x","name":"new","role":"image"},2,[true,false]],"passed":true},{"actual":[{"help":"h","name":""},2,[true,false]],"check":"contract fixture 2","expected":[{"help":"h"},2,[true,false]],"passed":false},{"actual":[{"id":"x","role":"image"},1,[false,false]],"check":"contract fixture 3","expected":[{"id":"x","role":"image"},1,[false,false]],"passed":true},{"actual":[{},2,[false,false,true]],"check":"contract fixture 4","expected":[{},2,[false,false,true]],"passed":true},{"actual":[{"name":"x"},1,[false]],"check":"contract fixture 5","expected":[{"name":"x"},1,[false]],"passed":true},{"actual":[{"description":"D","language":"en","name":"","value":"0"},2,[true]],"check":"contract fixture 6","expected":[{"description":"D","language":"en","value":"0"},2,[true]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"contract fixture 1\", \"actual\": [{\"id\": \"x\", \"role\": \"image\", \"name\": \"new\", \"help\": \"\"}, 2, [true, false]], \"expected\": [{\"id\": \"x\", \"role\": \"image\", \"name\": \"new\", \"help\": \"\"}, 2, [true, false]], \"passed\": true}, {\"check\": \"contract fixture 2\", \"actual\": [{\"name\": \"\", \"help\": \"h\"}, 2, [true, false]], \"expected\": [{\"help\": \"h\"}, 2, [true, false]], \"passed\": false}, {\"check\": \"contract fixture 3\", \"actual\": [{\"id\": \"x\", \"role\": \"image\"}, 1, [false, false]], \"expected\": [{\"id\": \"x\", \"role\": \"image\"}, 1, [false, false]], \"passed\": true}, {\"check\": \"contract fixture 4\", \"actual\": [{}, 2, [false, false, true]], \"expected\": [{}, 2, [false, false, true]], \"passed\": true}, {\"check\": \"contract fixture 5\", \"actual\": [{\"name\": \"x\"}, 1, [false]], \"expected\": [{\"name\": \"x\"}, 1, [false]], \"passed\": true}, {\"check\": \"contract fixture 6\", \"actual\": [{\"name\": \"\", \"description\": \"D\", \"value\": \"0\", \"language\": \"en\"}, 2, [true]], \"expected\": [{\"description\": \"D\", \"value\": \"0\", \"language\": \"en\"}, 2, [true]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.412,"exit_code":1,"observations":[{"actual":[{"help":"","id":"x","name":"new","role":"image"},2,[true,false]],"check":"contract fixture 1","expected":[{"help":"","id":"x","name":"new","role":"image"},2,[true,false]],"passed":true},{"actual":[{"help":"h","name":null},2,[true,false]],"check":"contract fixture 2","expected":[{"help":"h"},2,[true,false]],"passed":false},{"actual":[{"id":"x","role":"image"},1,[false,false]],"check":"contract fixture 3","expected":[{"id":"x","role":"image"},1,[false,false]],"passed":true},{"actual":[{},2,[false,false,true]],"check":"contract fixture 4","expected":[{},2,[false,false,true]],"passed":true},{"actual":[{"name":"x"},1,[false]],"check":"contract fixture 5","expected":[{"name":"x"},1,[false]],"passed":true},{"actual":[{"description":"D","language":"en","name":null,"value":"0"},2,[true]],"check":"contract fixture 6","expected":[{"description":"D","language":"en","value":"0"},2,[true]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"contract fixture 1\", \"actual\": [{\"id\": \"x\", \"role\": \"image\", \"name\": \"new\", \"help\": \"\"}, 2, [true, false]], \"expected\": [{\"id\": \"x\", \"role\": \"image\", \"name\": \"new\", \"help\": \"\"}, 2, [true, false]], \"passed\": true}, {\"check\": \"contract fixture 2\", \"actual\": [{\"name\": null, \"help\": \"h\"}, 2, [true, false]], \"expected\": [{\"help\": \"h\"}, 2, [true, false]], \"passed\": false}, {\"check\": \"contract fixture 3\", \"actual\": [{\"id\": \"x\", \"role\": \"image\"}, 1, [false, false]], \"expected\": [{\"id\": \"x\", \"role\": \"image\"}, 1, [false, false]], \"passed\": true}, {\"check\": \"contract fixture 4\", \"actual\": [{}, 2, [false, false, true]], \"expected\": [{}, 2, [false, false, true]], \"passed\": true}, {\"check\": \"contract fixture 5\", \"actual\": [{\"name\": \"x\"}, 1, [false]], \"expected\": [{\"name\": \"x\"}, 1, [false]], \"passed\": true}, {\"check\": \"contract fixture 6\", \"actual\": [{\"name\": null, \"description\": \"D\", \"value\": \"0\", \"language\": \"en\"}, 2, [true]], \"expected\": [{\"description\": \"D\", \"value\": \"0\", \"language\": \"en\"}, 2, [true]], \"passed\": false}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}