From 15f9ad6e88c33c8ea817a883a5a6eaab19143ed2 Mon Sep 17 00:00:00 2001
From: Jan Larres <jan@majutsushi.net>
Date: Wed, 6 Nov 2013 13:27:16 +1300
Subject: [PATCH] Check for existence of qf var before deleting

Otherwise explicit calling of QuickFixCmdPost autocmds without a
preceding QuickFixCmdPre will generate an error.
---
 autoload/tagbar.vim | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/autoload/tagbar.vim b/autoload/tagbar.vim
index 2682b43..a7a9b1d 100644
--- a/autoload/tagbar.vim
+++ b/autoload/tagbar.vim
@@ -979,7 +979,9 @@ function! s:CreateAutocommands() abort
                     \ s:known_files.rm(fnamemodify(expand('<afile>'), ':p'))
 
         autocmd QuickFixCmdPre  * let s:tagbar_qf_active = 1
-        autocmd QuickFixCmdPost * unlet s:tagbar_qf_active
+        autocmd QuickFixCmdPost * if exists('s:tagbar_qf_active') |
+                                \     unlet s:tagbar_qf_active |
+                                \ fi
 
         autocmd VimEnter * call s:CorrectFocusOnStartup()
     augroup END