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https://issues.apache.org/jira/browse/COMPRESS-380?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16315460#comment-16315460
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Dawid Weiss commented on COMPRESS-380:
--------------------------------------
Hi Stefan. Seems to be this assertion causing this particular problem:
{code}
if (memory[start] == -1) {
throw new IllegalStateException("Attempt to read beyond memory:
dist=" + distance);
}
{code}
{{memory}} is a byte array so {{0xff}} will trip this. I commented it out and
the test passes then. I'd remove this check entirely (and Array.fill(-1) too).
There are still plenty of other exceptions. For example the non-compressed
block header fails to verify on len/nlen equality. I think this condition is
wrong:
{code}
case 0:
readBits(Byte.SIZE - 3);
{code}
because the spec says:
{code}
Any bits of input up to the next byte boundary are ignored.
{code}
and while it is true on the first block, it may not be on subsequent blocks (I
think). The bit reader would have to be able to align to a byte boundary here.
I didn't check for other errors (there's still quite a few of them), but the
above is definitely a start for looking deeper.
> Support for ENHANCED_DEFLATED (Deflate64) in ZIP files
> ------------------------------------------------------
>
> Key: COMPRESS-380
> URL: https://issues.apache.org/jira/browse/COMPRESS-380
> Project: Commons Compress
> Issue Type: New Feature
> Reporter: Dawid Weiss
> Fix For: 1.16
>
> Attachments: archive-deflate.zip, archive-deflate64.zip, archive.zip,
> archive64.zip, compress-380.diff, hello.world, input2
>
>
> Some of the (large) ZIP files we try to process currently will throw this:
> {code}
> UnsupportedZipFeatureException: unsupported feature method
> 'ENHANCED_DEFLATED'
> {code}
> which is a bummer since JDK's implementation also doesn't support Deflate64.
> This seems to be PKWare's extensions, although code to decrypt it exists in
> zlib (and is appropriately licensed, I believe).
> https://github.com/madler/zlib/tree/master/contrib/infback9
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