FA-3011 / Text processing / Open access

Line terminators lose their original spelling · case 01

Line terminators lose their original spelling.

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: Split lines retaining complete CRLF and all other recognized terminators.

VERIFIED REPAIR

Implement the complete stated contract, including the boundary fixtures: Split lines retaining complete CRLF and all other recognized terminators.

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

Case contract

Split lines retaining complete CRLF and all other recognized terminators.

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 [v+'\n' for v in x.splitlines()]
    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\r\nb'), ['a\r\n', 'b'])
check('boundary 2', solve('a\n'), ['a\n'])
check('boundary 3', solve('a\u2028b'), ['a\u2028', 'b'])
check('boundary 4', solve(''), [])
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\n', 'b\n']`	`['a\r\n', 'b']`	Failed
boundary 2	`['a\n']`	`['a\n']`	Passed
boundary 3	`['a\n', 'b\n']`	`['a\u2028', 'b']`	Failed
boundary 4	`[]`	`[]`	Passed

SHA-256 / db2681556369ac772b30ed6d0a16310c938a9c09e16fd479a8948c6a5b8cff30

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 x.splitlines()
    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\r\nb'), ['a\r\n', 'b'])
check('boundary 2', solve('a\n'), ['a\n'])
check('boundary 3', solve('a\u2028b'), ['a\u2028', 'b'])
check('boundary 4', solve(''), [])
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', 'b']`	`['a\r\n', 'b']`	Failed
boundary 2	`['a']`	`['a\n']`	Failed
boundary 3	`['a', 'b']`	`['a\u2028', 'b']`	Failed
boundary 4	`[]`	`[]`	Passed

SHA-256 / 0453b36bcc1aa694a13ca803eb645e087af4d2df0c3c367baed2bc9a7e3feb76

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:
        return x.splitlines(True)
    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\r\nb'), ['a\r\n', 'b'])
check('boundary 2', solve('a\n'), ['a\n'])
check('boundary 3', solve('a\u2028b'), ['a\u2028', 'b'])
check('boundary 4', solve(''), [])
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\r\n', 'b']`	`['a\r\n', 'b']`	Passed
boundary 2	`['a\n']`	`['a\n']`	Passed
boundary 3	`['a\u2028', 'b']`	`['a\u2028', 'b']`	Passed
boundary 4	`[]`	`[]`	Passed

SHA-256 / e60de978963d4c17633dee2d51f192fc1748a2c9fd934bd2084b0c74924abb85

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 2026-09-29T14:37:20.407002+00:00.

Case digest / b711f28db0ad84588c3baf14798ad1ddbf24aea0a9685bc56e3473ba32e2b0d0