reset v:errmsg before checking cmdwin

mattn · mattn · commit d980d4d27593 · 2016-08-22T17:04:14.000+09:00
diff --git a/autoload/ctrlp.vim b/autoload/ctrlp.vim
@@ -2032,7 +2032,7 @@ fu! s:checkbuf()
 endf
 
 fu! s:iscmdwin()
-	let ermsg = v:errmsg
+	let [ermsg, v:errmsg] = [v:errmsg, '']
 	sil! noa winc p
 	sil! noa winc p
 	let [v:errmsg, ermsg] = [ermsg, v:errmsg]
