FA-8501 / Form submission / Open access

Successful form control collection: Multiple selections are submitted as one nested value · case 01

Multiple selections are submitted as one nested value.

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

ROOT CAUSE

The multiple operation uses `[c['value']]` where the contract requires `c['value'] if c['type'] == 'multiple' else [c['value']]`.

THE FAILURE

The multiple operation uses `[c['value']]` where the contract requires `c['value'] if c['type'] == 'multiple' else [c['value']]`.

Unsuccessful approach: Deduplicating selected values loses separate equal-valued options.

Case contract

Submit enabled named controls, checked choices and only the actual submitter; emit one ordered pair per selected multiple option without value deduplication.

Why this case matters

A deterministic model of successful form control collection; this isolates one interface invariant without requiring a browser.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(controls, submitter):
    pairs = []
    for c in controls:
        if c['disabled']: continue
        if not c['name']: continue
        if c['type'] in ('checkbox', 'radio') and not c['checked']: continue
        if c['type'] == 'submit' and c['id'] != submitter: continue
        values = [c['value']]
        pairs.extend((c['name'], value) for value in values)
    return pairs
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('disabled', solve([dict(disabled=True,name='a',type='text',checked=False,id='a',value='x')], None), [])
check('unnamed', solve([dict(disabled=False,name='',type='text',checked=False,id='a',value='x')], None), [])
check('unchecked', solve([dict(disabled=False,name='a',type='checkbox',checked=False,id='a',value='x')], None), [])
check('checked', solve([dict(disabled=False,name='a',type='checkbox',checked=True,id='a',value='x')], None), [('a', 'x')])
check('other submit', solve([dict(disabled=False,name='a',type='submit',checked=False,id='other',value='x')], 'actual'), [])
check('actual submit', solve([dict(disabled=False,name='a',type='submit',checked=False,id='actual',value='x')], 'actual'), [('a', 'x')])
check('multiple', solve([dict(disabled=False,name='a',type='multiple',checked=False,id='a',value=['x','x','y'])], None), [('a', 'x'), ('a', 'x'), ('a', 'y')])
check('parameterized submission value', solve([dict(disabled=False,name='a',type='text',checked=False,id='a',value=N)],None), [('a',N)])
for repetition in range(N):
    check('repeat multiple', solve([dict(disabled=False,name='a',type='multiple',checked=False,id='a',value=['x','x','y'])], None), [('a', 'x'), ('a', 'x'), ('a', 'y')])
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
disabled	`[]`	`[]`	Passed
unnamed	`[]`	`[]`	Passed
unchecked	`[]`	`[]`	Passed
checked	`[['a', 'x']]`	`[['a', 'x']]`	Passed
other submit	`[]`	`[]`	Passed
actual submit	`[['a', 'x']]`	`[['a', 'x']]`	Passed
multiple	`[['a', ['x', 'x', 'y']]]`	`[['a', 'x'], ['a', 'x'], ['a', 'y']]`	Failed
parameterized submission value	`[['a', 1]]`	`[['a', 1]]`	Passed
repeat multiple	`[['a', ['x', 'x', 'y']]]`	`[['a', 'x'], ['a', 'x'], ['a', 'y']]`	Failed

SHA-256 / 80fc8cdac1e7efe214585259126be0d816400185aebdf056360b41b8cd921d35

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(controls, submitter):
    pairs = []
    for c in controls:
        if c['disabled']: continue
        if not c['name']: continue
        if c['type'] in ('checkbox', 'radio') and not c['checked']: continue
        if c['type'] == 'submit' and c['id'] != submitter: continue
        values = list(set(c['value'])) if c['type'] == 'multiple' else [c['value']]
        pairs.extend((c['name'], value) for value in values)
    return pairs
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('disabled', solve([dict(disabled=True,name='a',type='text',checked=False,id='a',value='x')], None), [])
check('unnamed', solve([dict(disabled=False,name='',type='text',checked=False,id='a',value='x')], None), [])
check('unchecked', solve([dict(disabled=False,name='a',type='checkbox',checked=False,id='a',value='x')], None), [])
check('checked', solve([dict(disabled=False,name='a',type='checkbox',checked=True,id='a',value='x')], None), [('a', 'x')])
check('other submit', solve([dict(disabled=False,name='a',type='submit',checked=False,id='other',value='x')], 'actual'), [])
check('actual submit', solve([dict(disabled=False,name='a',type='submit',checked=False,id='actual',value='x')], 'actual'), [('a', 'x')])
check('multiple', solve([dict(disabled=False,name='a',type='multiple',checked=False,id='a',value=['x','x','y'])], None), [('a', 'x'), ('a', 'x'), ('a', 'y')])
check('parameterized submission value', solve([dict(disabled=False,name='a',type='text',checked=False,id='a',value=N)],None), [('a',N)])
for repetition in range(N):
    check('repeat multiple', solve([dict(disabled=False,name='a',type='multiple',checked=False,id='a',value=['x','x','y'])], None), [('a', 'x'), ('a', 'x'), ('a', 'y')])
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
disabled	`[]`	`[]`	Passed
unnamed	`[]`	`[]`	Passed
unchecked	`[]`	`[]`	Passed
checked	`[['a', 'x']]`	`[['a', 'x']]`	Passed
other submit	`[]`	`[]`	Passed
actual submit	`[['a', 'x']]`	`[['a', 'x']]`	Passed
multiple	`[['a', 'x'], ['a', 'y']]`	`[['a', 'x'], ['a', 'x'], ['a', 'y']]`	Failed
parameterized submission value	`[['a', 1]]`	`[['a', 1]]`	Passed
repeat multiple	`[['a', 'x'], ['a', 'y']]`	`[['a', 'x'], ['a', 'x'], ['a', 'y']]`	Failed

SHA-256 / 684c6615f17bfd1f9170dfb6d36bf2ceeedfa60423384d33072c2ad091f103e9

HELD IN THE MEMBER ARCHIVE

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

This mechanism has 9 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.

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Verification & scope

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 2026-09-29T14:38:21.983892+00:00.

Case digest / 4cd80d97b1d0445685a6ce61c3519464658c29b1aa9272c112a861778eef987e