use bundle.installed to check installation

autoload/vundle/installer.vim

@@ -62,10 +62,6 @@ func! s:helptags(rtp) abort
 endf
 
 
-func! s:installed(bundle) abort
-  return !empty(split(globpath(a:bundle.path(), '*'), "\n"))
-endf
-
 func! s:sync(bang, bundle) abort
   if a:bundle.nosync() | return 0 | endif
   if a:bundle.installed()

test/vimrc

@@ -47,7 +47,7 @@ BundleInstall
 
 func! s:assert_bundles() abort
   for b in g:vundle#bundles
-    if (!isdirectory(b.path().'/.git'))
+    if (!b.installed())
       throw b.name.' not installed'
     endif
   endfor