[issue30073] binary compressed file reading corrupts newlines (lzma, gzip, bz2)

[Julian Taylor]

New submission from Julian Taylor:

Probably a case of 'don't do that' but reading lines in a compressed files in binary mode produces bytes with invalid newlines in encodings that where '\n' is encoded as something else:

with lzma.open("test.xz", "wt", encoding="UTF-32-LE") as f:
    f.write('0 1 2\n3 4 5');

lzma.open("test.xz", "rb").readlines()[0].decode('UTF-32-LE')

Fails with:
UnicodeDecodeError: 'utf-32-le' codec can't decode byte 0x0a in position 20: truncated data

as readlines() produces:
b'0\x00\x00\x00 \x00\x00\x001\x00\x00\x00 \x00\x00\x002\x00\x00\x00\n'
The last newline should be '\n'.encode('UTF-32-LE') == b'\n\x00\x00\x00'

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components: Library (Lib)
messages: 291661
nosy: jtaylor
priority: normal
severity: normal
status: open
title: binary compressed file reading corrupts newlines (lzma, gzip, bz2)

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue30073>
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