The mystery is that, at one of our branches, it reduces size to 0, but is never actually removed; after which time the file cannot be edited until that lock file is manually removed.

Both servers have the same davfs2.conf and I have done a diff between the two servers:

# for file in `find /usr/lib/openoffice/ -name *.xcs -type f`; \
  do echo "=== $file ==="; \
  ssh root@other-server "cat $file" | diff $file - ; \
  done

But there are no differences.  I have checked users’ davfs2.conf files, but these are all commented out entirely.

Previously I had “fixed” this problem, by setting UseDocumentOOoLockFile to false in:

/usr/lib/openoffice/basis3.2/share/registry/schema/org/openoffice/Office/Common.xcs

This doesn’t stop the lock files being created, but it does tell Openoffice not to worry about them.  Unfortunately this no longer seems to be working, and I really can’t understand why.

Currently I have “fixed” the problem by setting davfs2.conf to:

use_locks 0

This is now allowing the lock files to be removed properly.  I believe that actually this will work quite well, with the UseDocumentOOoLockFile set to true, given that 99.9% of our documents are Openoffice documents.  Always assuming I can persuade Openoffice to obey its own registry!