Merge pull request Shougo#249 from tyru/exists-equals-to-2

Check if `exists(':cmdname')` == 2

autoload/dein/autoload.vim

@@ -157,7 +157,7 @@ endfunction
 function! dein#autoload#_on_cmd(command, name, args, bang, line1, line2) abort
   call dein#source(a:name)
 
-  if !exists(':' . a:command)
+  if exists(':' . a:command) != 2
     call dein#util#_error(printf('command %s is not found.', a:command))
     return
   endif
@@ -215,15 +215,15 @@ endfunction
 
 function! dein#autoload#_dummy_complete(arglead, cmdline, cursorpos) abort
   let command = matchstr(a:cmdline, '\h\w*')
-  if exists(':'.command)
+  if exists(':'.command) == 2
     " Remove the dummy command.
     silent! execute 'delcommand' command
   endif
 
   " Load plugins
   call dein#autoload#_on_pre_cmd(tolower(command))
 
-  if exists(':'.command)
+  if exists(':'.command) == 2
     " Print the candidates
     call feedkeys("\<C-d>", 'n')
   endif

autoload/dein/install.vim

@@ -412,7 +412,7 @@ function! dein#install#_remote_plugins() abort
   let &runtimepath = dein#util#_join_rtp(dein#util#_uniq(
         \ dein#util#_split_rtp(&runtimepath)), &runtimepath, '')
 
-  if exists(':UpdateRemotePlugins')
+  if exists(':UpdateRemotePlugins') == 2
     UpdateRemotePlugins
   endif
 endfunction