Additional chpwd clobbering fix for dirpersist

plugins/dirpersist/dirpersist.plugin.zsh

@@ -11,7 +11,9 @@ if [[ -f ${dirstack_file} ]] && [[ ${#dirstack[*]} -eq 0 ]] ; then
   [[ -d $dirstack[1] ]] && cd $dirstack[1] && cd $OLDPWD
 fi
 
-chpwd() {
+typeset -ga chpwd_functions
+chpwd_functions+='chpwd_dirpersist'
+chpwd_dirpersist() {
   if (( $DIRSTACKSIZE <= 0 )) || [[ -z $dirstack_file ]]; then return; fi
   local -ax my_stack
   my_stack=( ${PWD} ${dirstack} )