[Zope] zlib.error : huh?

[Shane Hathaway]

Aaron Straup Cope wrote:
> 
> I am trying to understand what exactly is going on when Zope returns an
> Error -5 page.
> 
> Normally, this only happens on the left hand navigational menu but today
> it happened while I was expanding an xml document/tree object from the
> Examples package for the XML Document product.
> 
> I've tried searching Google, the Zope site and the mailing list but to no
> avail. Could someone please explain what's going on here? Is it me? Is it
> Zope? How exactly do I prevent these errors from happening?

Here's my guess: you have a complex XML document.  As you explore the
document, Zope is setting a cookie that reflects the list of branches
you have opened.  After opening a large number of branches, you reach
the limit on the size of a cookie (somewhere in the range of 1024 or
4096 bytes), making it so that the compressed data stored in the cookie
gets truncated.  zlib then emits this cryptic error message.

Shane

> 
> Thanks,
> 
> Error Type: zlib.error
> Error Value: Error -5 while decompressing data: []
> 
> Traceback (innermost last):
>   File /usr/local/zope.old/lib/python/ZPublisher/Publish.py, line 222, in
> publish_module
>   File /usr/local/zope.old/lib/python/ZPublisher/Publish.py, line 187, in
> publish
>   File /usr/local/zope.old/lib/python/Zope/__init__.py, line 221, in
> zpublisher_exception_hook
>     (Object: Traversable)
>   File /usr/local/zope.old/lib/python/ZPublisher/Publish.py, line 171, in
> publish
>   File /usr/local/zope.old/lib/python/ZPublisher/mapply.py, line 160, in
> mapply
>     (Object: tree)
>   File /usr/local/zope.old/lib/python/ZPublisher/Publish.py, line 112, in
> call_object
>     (Object: tree)
>   File /usr/local/zope.old/lib/python/OFS/DTMLDocument.py, line 177, in
> __call__
>     (Object: tree)
>   File /usr/local/zope.old/lib/python/DocumentTemplate/DT_String.py, line
> 528, in __call__
>     (Object: tree)
>   File /usr/local/zope.old/lib/python/TreeDisplay/TreeTag.py, line 154, in
> render
>     (Object: test[0])
>   File /usr/local/zope.old/lib/python/TreeDisplay/TreeTag.py, line 229, in
> tpRender
>     (Object: Manageable)
>   File /usr/local/zope.old/lib/python/TreeDisplay/TreeTag.py, line 637, in
> decode_seq
> zlib.error: (see above)
> 
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