From c1adf0cd3df8b6ce4724678976eac6d87318c38d Mon Sep 17 00:00:00 2001
From: Marco Hinz <mh.codebro@gmail.com>
Date: Fri, 10 Apr 2015 22:18:46 +0200
Subject: [PATCH] Check if :FZF is already executing

Prior to this change, you'd get a longer error message if you did:

    :FZF
    <esc>
    :FZF

The main problem being that `:file [FZF]` can be used only once.
---
 plugin/fzf.vim | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/plugin/fzf.vim b/plugin/fzf.vim
index 9a942a0..2b56920 100644
--- a/plugin/fzf.vim
+++ b/plugin/fzf.vim
@@ -318,6 +318,12 @@ function! s:cmd_callback(lines) abort
 endfunction
 
 function! s:cmd(bang, ...) abort
+  if bufexists('[FZF]')
+    echohl WarningMsg
+    echomsg 'FZF is already running!'
+    echohl NONE
+    return
+  endif
   let args = copy(a:000)
   if !s:legacy
     let args = insert(args, '--expect=ctrl-t,ctrl-x,ctrl-v', 0)