a bug / mis-feature in ra_serf

Hello,

I found an issue with the ra_serf SVN module. The problem is that
during the commit via ra_serf it tries to keep all files open (or
something like this), so if there is a limit on number of open files
and it's lower that the number of files to commit, then SVN client
fails with:
===
svn: Commit failed (details follow):
svn: Can't find a temporary directory: Internal error
===

To reproduce the issue one need to create an empty repository, check it
out via HTTP/HTTPS, then populate with, say, 2000 files. At this
point, set the number of open files limit to 1024 (ulimit -n 1024).
After this if you try to commit them back it will work perfectly with
ra_neon, but will fail if you are using ra_serf.

I've verified this with the latest version of Subversion (1.6.9), the
latest version of neon (0.29.3), and serf 0.30 (I had no time to build
and verify version 0.31, sorry).

Hope this helps.

-- 
Dmitry D. Khlebnikov
Openwall [http://openwall.com]