FA-3206 / Delimited text / Open access

An unclosed quoted CSV field is accepted · case 01

An unclosed quoted CSV field is accepted.

Verified by executionVariant 1 · 4 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The implementation applies an operation whose text or grammar semantics violate this contract: Read one CSV record in strict mode; malformed quoting returns None.

VERIFIED REPAIR

Implement the complete stated contract, including the boundary fixtures: Read one CSV record in strict mode; malformed quoting returns None.

Unsuccessful approach: The attempted repair handles the primary example but still violates a separate boundary of the same contract.

Case contract

Read one CSV record in strict mode; malformed quoting returns None.

Why this case matters

A local executable model for consumers of structured text; oracle values are authored literals, not outputs copied from the repaired implementation.

1 / The failure

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return next(csv.reader([x]))
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('"a'), None)
check('boundary 2', solve('"a"z'), None)
check('boundary 3', solve('"a""b"'), ['a"b'])
check('boundary 4', solve('a,b'), ['a', 'b'])
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
boundary 1	`['a']`	`None`	Failed
boundary 2	`['az']`	`None`	Failed
boundary 3	`['a"b']`	`['a"b']`	Passed
boundary 4	`['a', 'b']`	`['a', 'b']`	Passed

SHA-256 / ce9b6e0abe5c576360f938bbc19b82cc9d870a6942d127beeaa37b2401067819

2 / The unsuccessful fix

Exit 1

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        return None if x.count('"')%2 else next(csv.reader([x]))
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('"a'), None)
check('boundary 2', solve('"a"z'), None)
check('boundary 3', solve('"a""b"'), ['a"b'])
check('boundary 4', solve('a,b'), ['a', 'b'])
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
boundary 1	`None`	`None`	Passed
boundary 2	`['az']`	`None`	Failed
boundary 3	`['a"b']`	`['a"b']`	Passed
boundary 4	`['a', 'b']`	`['a', 'b']`	Passed

SHA-256 / e3e4945da5045590902b6c9cf4e0ddb86bf3adef7a9473749688e1a53f1e68b9

3 / The verified repair

Exit 0

"""Failure Map reference implementation. Python standard library only."""
import json
import re, unicodedata, json, csv, io, html, base64, binascii, codecs, struct
from urllib.parse import quote, unquote, unquote_to_bytes, urlencode, parse_qsl, urlsplit, urlunsplit
from email.header import decode_header, make_header
from email.utils import getaddresses
from xml.etree import ElementTree as ET
import shlex, string, textwrap

N = 1
observations = []
def solve(x):
    try:
        try:
            return next(csv.reader([x],strict=True))
        except csv.Error:
            return None
    except Exception as exc:
        return {"error": type(exc).__name__}
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('boundary 1', solve('"a'), None)
check('boundary 2', solve('"a"z'), None)
check('boundary 3', solve('"a""b"'), ['a"b'])
check('boundary 4', solve('a,b'), ['a', 'b'])
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
boundary 1	`None`	`None`	Passed
boundary 2	`None`	`None`	Passed
boundary 3	`['a"b']`	`['a"b']`	Passed
boundary 4	`['a', 'b']`	`['a', 'b']`	Passed

SHA-256 / 3818a44f30708916cc196fd0ebd6a59cdf921d68b02004f08de091e75af6dc83

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 2026-09-29T14:37:22.555287+00:00.

Case digest / a01e7b8e9877363822ee19bcf0f5390e9f842785bf1ca0aa5862f614209d5452