[issue3790] in zlib decompressor objects, unused_data and unconsumed_tail must be immutable

[Antoine Pitrou]

New submission from Antoine Pitrou <pitrou at free.fr>:

Currently (in py3k), the attributes "unused_data" and "unconsumed_tail"
on zlib decompressor objects are bytearrays. This can wreak havoc in the
read() method of ZipInfo objects, because one of those bytearrays is
assigned to the internal "rawbuffer" and then extended using "+="...
leading to wrong results (right now I can only reproduce it on a 3.5 GB
zip file, sorry :-( ).

Here is a patch.

----------
components: Extension Modules
files: zlib_unconsumed_tail.patch
keywords: needs review, patch, patch
messages: 72652
nosy: pitrou
priority: critical
severity: normal
status: open
title: in zlib decompressor objects, unused_data and unconsumed_tail must be immutable
type: behavior
versions: Python 3.0
Added file: http://bugs.python.org/file11403/zlib_unconsumed_tail.patch

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue3790>
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