+# The following is the ‘add-zsh-hook’ function from zsh upstream. It is
+# included here to make the setup work with older versions of zsh (prior to
+# 4.3.7) in which this function had a bug that triggers annoying errors during
+# shell startup. This is exactly upstreams code from f0068edb4888a4d8fe94def,
+# with just a few adjustments in coding style to make the function look more
+# compact. This definition can be removed as soon as we raise the minimum
+# version requirement to 4.3.7 or newer.
+function add-zsh-hook () {
+ # Add to HOOK the given FUNCTION.
+ # HOOK is one of chpwd, precmd, preexec, periodic, zshaddhistory,
+ # zshexit, zsh_directory_name (the _functions subscript is not required).
+ #
+ # With -d, remove the function from the hook instead; delete the hook
+ # variable if it is empty.
+ #
+ # -D behaves like -d, but pattern characters are active in the function
+ # name, so any matching function will be deleted from the hook.
+ #
+ # Without -d, the FUNCTION is marked for autoload; -U is passed down to
+ # autoload if that is given, as are -z and -k. (This is harmless if the
+ # function is actually defined inline.)
+ emulate -L zsh
+ local -a hooktypes
+ hooktypes=(
+ chpwd precmd preexec periodic zshaddhistory zshexit
+ zsh_directory_name
+ )
+ local usage="Usage: $0 hook function\nValid hooks are:\n $hooktypes"
+ local opt
+ local -a autoopts
+ integer del list help
+ while getopts "dDhLUzk" opt; do
+ case $opt in
+ (d) del=1 ;;
+ (D) del=2 ;;
+ (h) help=1 ;;
+ (L) list=1 ;;
+ ([Uzk]) autoopts+=(-$opt) ;;
+ (*) return 1 ;;
+ esac
+ done
+ shift $(( OPTIND - 1 ))
+ if (( list )); then
+ typeset -mp "(${1:-${(@j:|:)hooktypes}})_functions"
+ return $?
+ elif (( help || $# != 2 || ${hooktypes[(I)$1]} == 0 )); then
+ print -u$(( 2 - help )) $usage
+ return $(( 1 - help ))
+ fi
+ local hook="${1}_functions"
+ local fn="$2"
+ if (( del )); then
+ # delete, if hook is set
+ if (( ${(P)+hook} )); then
+ if (( del == 2 )); then
+ set -A $hook ${(P)hook:#${~fn}}
+ else
+ set -A $hook ${(P)hook:#$fn}
+ fi
+ # unset if no remaining entries --- this can give better
+ # performance in some cases
+ if (( ! ${(P)#hook} )); then
+ unset $hook
+ fi
+ fi
+ else
+ if (( ${(P)+hook} )); then
+ if (( ${${(P)hook}[(I)$fn]} == 0 )); then
+ set -A $hook ${(P)hook} $fn
+ fi
+ else
+ set -A $hook $fn
+ fi
+ autoload $autoopts -- $fn
+ fi
+}
+