The current wcng code, format 22, puts all working nodes at op-depth=2. The full op-depth code is enabled by defining SVN_WC__OP_DEPTH and, although no schema changes are involved, the way the database is used makes in incompatible with format 22 clients if working nodes are present. So SVN_WC__OP_DEPTH will involve a format bump to 23.
My current plan is to upgrade working copies automatically only if they have no working nodes, i.e. no tree changes via add, delete, copy, etc. Text and property modifications do not count as tree changes. Working copies that have tree changes will need to be upgraded by running diff/revert with a format 22 client followed by patch with a format 23 client. Automatically upgrading with working nodes would involve rewriting the op-depth and presence of the working nodes, as well as inserting some additional working nodes. While it would be possible to write this code, it's lot of work for a small return. It's only going to affect a few developers. The 22-to-23 upgrade is distinct from the 1.6-to-wcng upgrade. The 1.6 upgrade is the one that is important for general users. It will, eventually, support upgrading with 1.6 tree changes. The SVN_WC__OP_DEPTH code now passes all the regression tests apart from db-test 7 and upgrade_tests 15, both of which expect the pre-op-depth behaviour. My current plan is that format bump will occur towards the end of this week. -- Philip
