branch: make it work with vim74

closes #1907

autoload/airline/async.vim

@@ -64,13 +64,17 @@ function! airline#async#vcs_untracked(config, file, vcs)
   endif
 endfunction
 
+function! s:set_clean_variables(file, vcs)
+  let var=getbufvar(fnameescape(a:file), 'buffer_vcs_config', {})
+  let var[a:vcs].dirty=1
+  call setbufvar(fnameescape(a:file), 'buffer_vcs_config', var)
+  unlet! b:airline_head
+endfunction
+
 function! s:on_exit_clean(...) dict abort
   let buf=self.buf
   if !empty(buf)
-    let var=getbufvar(fnameescape(self.file), 'buffer_vcs_config', {})
+    call s:set_clean_variables(self.file, self.vcs)
-    let var[self.vcs].dirty=1
-    call setbufvar(fnameescape(self.file), 'buffer_vcs_config', var)
-    unlet! b:airline_head
   endif
   if has_key(get(s:clean_jobs, 'self.vcs', {}), self.file)
     call remove(s:clean_jobs[self.vcs], self.file)
@@ -255,32 +259,6 @@ elseif has("nvim")
     let s:mq_jobs[a:file] = id
   endfunction
 
-  function! airline#async#nvim_vcs_clean(cmd, file, vcs)
-    let config = {
-    \ 'buf': '',
-    \ 'vcs': a:vcs,
-    \ 'file': a:file,
-    \ 'cwd': s:valid_dir(fnamemodify(a:file, ':p:h')),
-    \ 'on_stdout': function('s:nvim_output_handler'),
-    \ 'on_stderr': function('s:nvim_output_handler'),
-    \ 'on_exit': function('s:on_exit_clean')
-    \ }
-    if g:airline#init#is_windows && &shell =~ 'cmd'
-      let cmd = a:cmd
-    else
-      let cmd = ['sh', '-c', a:cmd]
-    endif
-
-    if !has_key(s:clean_jobs, a:vcs)
-      let s:clean_jobs[a:vcs] = {}
-    endif
-    if has_key(s:clean_jobs[a:vcs], a:file)
-      call remove(s:clean_jobs[a:vcs], a:file)
-    endif
-    let id = jobstart(cmd, config)
-    let s:clean_jobs[a:vcs][a:file] = id
-  endfunction
-
   function! airline#async#nvim_get_msgfmt_stat(cmd, file)
     let config = {
     \ 'buf': '',
@@ -340,3 +318,37 @@ function! airline#async#nvim_vcs_untracked(cfg, file, vcs)
     call airline#extensions#branch#update_untracked_config(a:file, a:vcs)
   endif
 endfunction
+
+function! airline#async#nvim_vcs_clean(cmd, file, vcs)
+  let config = {
+  \ 'buf': '',
+  \ 'vcs': a:vcs,
+  \ 'file': a:file,
+  \ 'cwd': s:valid_dir(fnamemodify(a:file, ':p:h'))}
+  if has("nvim")
+    call extenc(config, {
+    \ 'on_stdout': function('s:nvim_output_handler'),
+    \ 'on_stderr': function('s:nvim_output_handler'),
+    \ 'on_exit': function('s:on_exit_clean')})
+    if g:airline#init#is_windows && &shell =~ 'cmd'
+      let cmd = a:cmd
+    else
+      let cmd = ['sh', '-c', a:cmd]
+    endif
+
+    if !has_key(s:clean_jobs, a:vcs)
+      let s:clean_jobs[a:vcs] = {}
+    endif
+    if has_key(s:clean_jobs[a:vcs], a:file)
+      call remove(s:clean_jobs[a:vcs], a:file)
+    endif
+    let id = jobstart(cmd, config)
+    let s:clean_jobs[a:vcs][a:file] = id
+  else
+    " Vim pre 8
+    let output=system(a:cmd)
+    if !empty(output)
+      call s:set_clean_variables(a:file, a:vcs)
+    endif
+  endif
+endfunction