[Zope] Problem with long "File" objects. FreeBSD/Zope-2.1.X

[Steve Spicklemire]

Hi Folks,

   OK.. I've narrowed this down.. but I think I've nearly reached the limit of 
what I can do easily. ;-) There appears to be some problem with ZServer and
long "File" objects under FreeBSD (3.2 in my case) and 2.1.X. When I go back
to 2.0.1 all is well... the chunk of code that *seems* to matter here is in
lib/python/OFS/Image.py:

        RESPONSE.setHeader('Content-Length', self.size)

        data=self.data
        if type(data) is type(''): return data

        while data is not None:
            RESPONSE.write(data.data)
            data=data.next

        return ''

in 2.0.1 this is just:

       return self.data


Here's the wierd part. When I step through this code with the debugger
it works! When I try to get a large object (that I've uploaded after
2.1.X) with a browser, e.g., lynx, or netscape I get a few chunks, and 
then the download stops. If I take this code out and replace it with the
2.0.1 code, it works. And another wierd part.. if I try to get an
object that was already in Zope *before* I upgraded.. it works too!
Hmmm.. stepping throught the debugger with such an object I discovered
the reason why... in 2.0.1 large uploaded objects were stored as a
single massive chunk... now they are multiple chunks... for some reason
multiple chunks do not work reliably in this context. I think it might be
a timing problem here is my 'testing.py' file I've been using for debugging:

----------------------------------------------------------------------
import sys

sys.path.insert(0,'/usr/local/etc/Zope/lib/python')

import ZPublisher

print ZPublisher.Zope("/largeFileObject", d=1, u="")

----------------------------------------------------------------------

I set d=1 to step through and d=0 to run from the command line.

if I try:

python testing.py | more

I get only one chunk.. and then the output stops. (something about timing and
the pipe?). If I try:

python testing.py > foo

I get the whole file in foo. (correct headers and all BTW). 

Anyway.. I need to get this resolved. Any hints on trying to track down
the problem would be most appreciated!

thanks,
-steve