Upgraded vim-plug plugin

via :PlugUpgrade

.vim/autoload/plug.vim

@@ -372,8 +372,10 @@ function! plug#end()
 
   for [cmd, names] in items(lod.cmd)
     execute printf(
-    \ 'command! -nargs=* -range -bang -complete=file %s call s:lod_cmd(%s, "<bang>", <line1>, <line2>, <q-args>, %s)',
-    \ cmd, string(cmd), string(names))
+    \ has('patch-7.4.1898')
+    \ ? 'command! -nargs=* -range -bang -complete=file %s call s:lod_cmd(%s, "<bang>", <line1>, <line2>, <q-args>, <q-mods> ,%s)'
+    \ : 'command! -nargs=* -range -bang -complete=file %s call s:lod_cmd(%s, "<bang>", <line1>, <line2>, <q-args>, %s)'
+    \ , cmd, string(cmd), string(names))
   endfor
 
   for [map, names] in items(lod.map)
@@ -651,11 +653,19 @@ function! s:lod_ft(pat, names)
   call s:doautocmd('filetypeindent', 'FileType')
 endfunction
 
+if has('patch-7.4.1898')
+  function! s:lod_cmd(cmd, bang, l1, l2, args, mods, names)
+    call s:lod(a:names, ['ftdetect', 'after/ftdetect', 'plugin', 'after/plugin'])
+    call s:dobufread(a:names)
+    execute printf('%s %s%s%s %s', a:mods, (a:l1 == a:l2 ? '' : (a:l1.','.a:l2)), a:cmd, a:bang, a:args)
+  endfunction
+else
   function! s:lod_cmd(cmd, bang, l1, l2, args, names)
     call s:lod(a:names, ['ftdetect', 'after/ftdetect', 'plugin', 'after/plugin'])
     call s:dobufread(a:names)
     execute printf('%s%s%s %s', (a:l1 == a:l2 ? '' : (a:l1.','.a:l2)), a:cmd, a:bang, a:args)
   endfunction
+endif
 
 function! s:lod_map(map, names, with_prefix, prefix)
   call s:lod(a:names, ['ftdetect', 'after/ftdetect', 'plugin', 'after/plugin'])
@@ -1075,12 +1085,16 @@ function! s:hash_match(a, b)
   return stridx(a:a, a:b) == 0 || stridx(a:b, a:a) == 0
 endfunction
 
+function! s:disable_credential_helper()
+  return s:git_version_requirement(2) && get(g:, 'plug_disable_credential_helper', 1)
+endfunction
+
 function! s:checkout(spec)
   let sha = a:spec.commit
   let output = s:git_revision(a:spec.dir)
   let error = 0
   if !empty(output) && !s:hash_match(sha, s:lines(output)[0])
-    let credential_helper = s:git_version_requirement(2) ? '-c credential.helper= ' : ''
+    let credential_helper = s:disable_credential_helper() ? '-c credential.helper= ' : ''
     let output = s:system(
           \ 'git '.credential_helper.'fetch --depth 999999 && git checkout '.plug#shellescape(sha).' --', a:spec.dir)
     let error = v:shell_error
@@ -1589,7 +1603,7 @@ while 1 " Without TCO, Vim stack is bound to explode
     let [error, _] = s:git_validate(spec, 0)
     if empty(error)
       if pull
-        let cmd = s:git_version_requirement(2) ? ['git', '-c', 'credential.helper=', 'fetch'] : ['git', 'fetch']
+        let cmd = s:disable_credential_helper() ? ['git', '-c', 'credential.helper=', 'fetch'] : ['git', 'fetch']
         if has_tag && !empty(globpath(spec.dir, '.git/shallow'))
           call extend(cmd, ['--depth', '99999999'])
         endif