Fix the problem that change_dir_prop always tries to create an svn_string_t even when local_value is NULL (which means deleting property).
Fix the problem that change_dir_prop always tries to create an
svn_string_t even when local_value is NULL (which means deleting
property).

Patch by: Yoshiki Hayashi <yoshiki@xemacs.org>

* get_editor.c (change_dir_prop): When local_value is NULL, simply set
  propchange->value to NULL.

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