scrooloose/syntastic — pull request #262 by powerman (2012-05-26 12:28:10+00:00)
Title: Fix E855 on :lclose

Since 7.3.449 trying to :lclose inside BufWinLeave result in E855:

$ vi -u /dev/null --noplugin -N
:autocmd BufWinLeave * if empty(&bt) | lclose | endif
:lexpr(':1:msg') | lopen | wincmd p | lclose
E855: Autocommands caused command to abort

$ vi -u /dev/null --noplugin -N
:autocmd BufWinLeave * if empty(&bt) | lclose | endif
:lexpr(':1:msg') | lopen | wincmd p | q
E855: Autocommands caused command to abort

Another issue with this autocmd is &bt in BufWinLeave may be different from
the buffer being unloaded (this is documented behaviour for BufWinLeave).
Replacing &bt with getbufvar(0+expand(''), '&bt') solve this, but
doesn't fix issue with E855 completely (first of above examples with
:lclose is fixed, but second with :q is not fixed).

So, to work around E855 I've changed way to close location-list:
instead of closing it on BufWinLeave, it's closed on BufEnter into
location-list window if it's only buffer in current window.