Return an error, rather than assert, for upgrades involving replaced directories that are copies.
Return an error, rather than assert, for upgrades involving replaced
directories that are copies.

* subversion/libsvn_wc/entries.c
  (write_entry): Return error rather than assert.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion