Verify zle is active before trying to reset-prompt.

plugins/vi-mode/vi-mode.plugin.zsh

@@ -17,9 +17,13 @@ function zle-keymap-select zle-line-init zle-line-finish {
 # Ensure that the prompt is redrawn when the terminal size changes.
 TRAPWINCH() {
   if [[ -o zle ]]; then
+    # Verify that zle is active before trying to reset-prompt.
+    zle
+    if [[ $? -eq 0 ]]; then
       zle reset-prompt
       zle -R
     fi
+  fi
 }
 
 zle -N zle-line-init