[horde] Imagemagick's convert consuming 100% CPU forever - from IMP

[D G Teed]

There is at least one bug in Imagemagick where CPU resources
are completely consumed and the conversion doesn't terminate.
It looks like this from ps, in case anyone was curious...

apache   19659 62.1 12.7 1961472 514756 ?      D    03:48 210:12
/usr/bin/convert -size 96x96 -resize 96x96 /tmp/imgsM8iAs[0] +profile *
png:/tmp/imgjPUEOK

I checked into this and there are several ways to limit the resources
of Imagemagick.  I thought I had a solution when I added a line
in my apache init script:
    export MAGICK_TIME_LIMIT=120
That should cause convert to kill itself after 120 seconds.
I verified within phpinfo output the environment variable took.

The next day the same problem appeared, so this isn't a solution.

I've considered making a .magick directory in apache's home and adding
some configuration .xml policy files there.  I don't know
how I could verify those took hold.

Is there another approach people have used?  Can we add
environment variables to the horde configuration where we
list the convert program?

I'm not sure how to test this.  The problem might trigger
for PDF thumbnails but I have not been able to reproduce
the issue with sample PDFs I've mailed to myself.