fzf: fzf causes splash when press ^R

• I have read through the manual page (man fzf)
• I have the latest version of fzf
• I have searched through the existing issues

Info

• OS
  • Linux - Arch linux latest
  • Mac OS X
  • Windows
  • Etc.
• Shell
  • bash
  • zsh
  • fish

Problem / Steps to reproduce

I have below code:

# CTRL-R - Paste the selected command from history into the command line
fzf-history-widget() {
  local selected num
  setopt localoptions noglobsubst noposixbuiltins pipefail no_aliases 2> /dev/null
  selected=( $(fc -rl 1 |
    FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} $FZF_DEFAULT_OPTS -n2..,.. --tiebreak=index --bind=ctrl-r:toggle-sort $FZF_CTRL_R_OPTS --query=${(qqq)LBUFFER} +m" $(__fzfcmd)) )
  local ret=$?
  if [ -n "$selected" ]; then
    num=$selected[1]
    if [ -n "$num" ]; then
      zle vi-fetch-history -n $num
    fi
  fi
  zle reset-prompt
  return $ret
}
zle     -N   fzf-history-widget
bindkey '^R' fzf-history-widget

that is in https://github.com/junegunn/fzf/blob/f7b26b34cbaf5a385bca8b6dd14eb5981e42d133/shell/key-bindings.zsh#L67

Notice the issue:

fc -rl 1 |
    FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} $FZF_DEFAULT_OPTS -n2..,.. --tiebreak=index --bind=ctrl-r:toggle-sort $FZF_CTRL_R_OPTS --query=${(qqq)LBUFFER} +m" $(__fzfcmd)

If I use fc as above, then fzf draw okay (meaning it will do only one draw).

If I use as below (need to get result from the fc command):

selected=( $(fc -rl 1 |
    FZF_DEFAULT_OPTS="--height ${FZF_TMUX_HEIGHT:-40%} $FZF_DEFAULT_OPTS -n2..,.. --tiebreak=index --bind=ctrl-r:toggle-sort $FZF_CTRL_R_OPTS --query=${(qqq)LBUFFER} +m" $(__fzfcmd)) )

Then the prompt somehow give a double re-draw, causing quick splash/flick/flash.

So I don’t know what is the cause of this behavior, why putting them into a subshell causing the issue? or this is from fc command itself?

I tried to use fzy for test and fzy does not causing splash that is in subshell:

selected=$(fc -rl 1 | fzy)