zsh: pass through exit code from widgets

This allows to have a custom widget like the following, which would
additionally accept the line, but only in case of entries being
selected:

    fzf-file-widget-with-accept() {
      zle fzf-file-widget
      if [[ "$?" == 0 ]] && (( $#BUFFER )); then
        zle accept-line
      fi
    }
    zle     -N   fzf-file-widget-with-accept
    bindkey '\e^T' fzf-file-widget-with-accept

With this `<C-a>t` will launch fzf, and simulate the pressing of "Enter"
afterwards.

shell/key-bindings.zsh

@@ -8,10 +8,13 @@ __fsel() {
     -o -type f -print \
     -o -type d -print \
     -o -type l -print 2> /dev/null | sed 1d | cut -b3-"}"
+  setopt localoptions pipefail
   eval "$cmd | $(__fzfcmd) -m $FZF_CTRL_T_OPTS" | while read item; do
     echo -n "${(q)item} "
   done
+  local ret=$?
   echo
+  return $ret
 }
 
 __fzfcmd() {
@@ -20,7 +23,9 @@ __fzfcmd() {
 
 fzf-file-widget() {
   LBUFFER="${LBUFFER}$(__fsel)"
+  local ret=$?
   zle redisplay
+  return $ret
 }
 zle     -N   fzf-file-widget
 bindkey '^T' fzf-file-widget
@@ -29,8 +34,11 @@ bindkey '^T' fzf-file-widget
 fzf-cd-widget() {
   local cmd="${FZF_ALT_C_COMMAND:-"command find -L . \\( -path '*/\\.*' -o -fstype 'dev' -o -fstype 'proc' \\) -prune \
     -o -type d -print 2> /dev/null | sed 1d | cut -b3-"}"
+  setopt localoptions pipefail
   cd "${$(eval "$cmd | $(__fzfcmd) +m $FZF_ALT_C_OPTS"):-.}"
+  local ret=$?
   zle reset-prompt
+  return $ret
 }
 zle     -N    fzf-cd-widget
 bindkey '\ec' fzf-cd-widget
@@ -38,8 +46,9 @@ bindkey '\ec' fzf-cd-widget
 # CTRL-R - Paste the selected command from history into the command line
 fzf-history-widget() {
   local selected num
-  setopt localoptions noglobsubst
+  setopt localoptions noglobsubst pipefail
   selected=( $(fc -l 1 | eval "$(__fzfcmd) +s --tac +m -n2..,.. --tiebreak=index --toggle-sort=ctrl-r $FZF_CTRL_R_OPTS -q ${(q)LBUFFER}") )
+  local ret=$?
   if [ -n "$selected" ]; then
     num=$selected[1]
     if [ -n "$num" ]; then
@@ -47,6 +56,7 @@ fzf-history-widget() {
     fi
   fi
   zle redisplay
+  return $ret
 }
 zle     -N   fzf-history-widget
 bindkey '^R' fzf-history-widget