patch 7.4.2134
Problem:    No error for using function() badly.
Solution:   Check for passing wrong function name. (Ken Takata)
diff --git a/src/evalfunc.c b/src/evalfunc.c
index 9905d0b..13864ea 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -2845,7 +2845,7 @@
     }
     else if (*p == '*')			/* internal or user defined function */
     {
-	n = function_exists(p + 1);
+	n = function_exists(p + 1, FALSE);
     }
     else if (*p == ':')
     {
@@ -3577,7 +3577,7 @@
 	EMSG2(_(e_invarg2), s);
     /* Don't check an autoload name for existence here. */
     else if (use_string && vim_strchr(s, AUTOLOAD_CHAR) == NULL
-						       && !function_exists(s))
+						&& !function_exists(s, TRUE))
 	EMSG2(_("E700: Unknown function: %s"), s);
     else
     {