wc-ng: determine if a node is versioned

Hi all,

I see a potential problem in the use of svn_wc__node_get_kind(): incomplete
state due to an interrupted operation.

Let's see the return values for svn_wc__node_get_kind(). It is quite
indistinguishable whether a node is not versioned, or whether it is
versioned but in incomplete state:

BASE or | one or | the | node is | show_ | Returned value
WORKING | both are | kind | hidden | hidden |
node | incomplete | is set | | arg is |
exists | | | | TRUE |
-------------------------------------------------------------------
 1| no - - - * | svn_node_unknown
 2| yes incomplete no - * | svn_node_unknown
 3| yes complete yes hidden no | svn_node_none
 4| yes complete yes hidden yes | _dir/_file
 5| yes complete yes not hidden * | _dir/_file
 6| yes incomplete yes - * | _dir/_file (relevant?)

At first glance, it appears that different code paths want to handle
incomplete nodes differently. Some want to act as if the node was 'normal'
== versioned. Most appear to want to act as if incomplete nodes were
non-versioned -- but maybe they just do that now because a cleanly
non-versioned node returns the same value as an incomplete node. And that's
the problem -- the API tempts hackers to just ignore the incomplete state
without reflection.

Maybe svn_wc__node_get_kind() should use determine if a node is incomplete
and throw an error if so, including a boolean arg allow_incomplete to bypass
that error?

What do the wc-ng gurus think about this?

Thanks,
~Neels