Be smarter about setting terminal keypad mode

Fixes issue #273.

module/.autocomplete.key

@@ -3,32 +3,28 @@ zmodload -Fa zsh/terminfo b:echoti p:terminfo
 builtin autoload -Uz add-zle-hook-widget
 
 .autocomplete.key.precmd() {
-  if [[ -v terminfo[rmkx] ]]; then
-    .autocomplete.key.normal-mode() {
-      echoti rmkx
-      return 0
-    }
-    add-zle-hook-widget line-init .autocomplete.key.normal-mode
-  fi
+  .autocomplete.key.set-keypad-mode() {
+    echoti ${${${key[Up]:#$terminfo[kcuu1]}:+rmkx}:-smkx} 2> /dev/null
+    return 0
+  }
+  add-zle-hook-widget line-init .autocomplete.key.set-keypad-mode
 }
 
 if [[ ${(t)key} != association ]]; then
   unset key
   typeset -gA key=()
 fi
 
-key+=(
-    Control-Space $'\0'
-    Tab           $'\t'
-    Return        $'\r'
-    Escape        $'\e'
-    Up            $'\e[A'
-    Down          $'\e[B'
-    Right         $'\e[C'
-    Left          $'\e[D'
-    End           $'\e[F'
-    Home          $'\e[H'
-    Shift-Tab     $'\e[Z'
-    PageUp        $'\e[5~'
-    PageDown      $'\e[6~'
-)
+: ${key[Control-Space]:=$'\0'}
+: ${key[Tab]:=$'\t'}
+: ${key[Return]:=$'\r'}
+: ${key[Escape]:=$'\e'}
+: ${key[Up]:=$'\e[A'}
+: ${key[Down]:=$'\e[B'}
+: ${key[Right]:=$'\e[C'}
+: ${key[Left]:=$'\e[D'}
+: ${key[End]:=$'\e[F'}
+: ${key[Home]:=$'\e[H'}
+: ${key[Shift-Tab]:=$'\e[Z'}
+: ${key[PageUp]:=$'\e[5~'}
+: ${key[PageDown]:=$'\e[6~'}