Etcd v 0.3 introduced the "prevNode" property that is handled strangely for dirs; if we update a dir we obtain a strange result returned:

c = etcd.Client()
r = c.write('/foo', None, dir=True, ttl=50)
print(r.dir) #True
r2 = c.write('/foo', None, dir=True, ttl=120, prevExist=True)
print(r2.dir) #False

We should somehow use what is in prevNode to understand if the node is a dir.

I strongly suspect this is not the only case in which the write() response does something funny.