[Zope] popen2 problem with Zope 2.7.0 and Photo

[Troy Farrell]

Greetings Zopistas.
Since I've upgraded from 2.6.2 to 2.7.0, the following product code causes
zope to hang:

  elif engine == 'ImageMagick':  # Use ImageMagick
    if sys.platform == 'win32':
      from win32pipe import popen2
      imgin, imgout = popen2('convert -quality %s -geometry %sx%s - -'
                             % (quality, width, height), 'b')
    else:
      print "Started popen2\n"
      from popen2 import popen2
      imgout, imgin = popen2('convert -quality %s -geometry %sx%s - -'
                             % (quality, width, height))
    print "Writing to stdin"
    imgin.write(origimg._IMdata())
    print "Finished writing to stdin\n"
    imgin.close()
    newimg.write(imgout.read())
    imgout.close()

When I run zope in debug mode, I see "Started popen2" and the "Writing to
stdin", but the process never gets to "Finished writing to stdin." 
Furthermore, zope will no longer respond to requests until I restart it. 
I already verified that origimg._IMdata() doesn't hang.  I am using Photo
1.2.3 from http://zope.org/Members/rbickers/Photo/ with ImageMagick on
Linux 2.2.20.

Any hints?

Thanks.
Troy