patch 7.4.1913
Problem:    When ":doautocmd" is used modelines are used even when no
            autocommands were executed. (Daniel Hahler)
Solution:   Skip processing modelines. (closes #854)
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index 2c7742e..5e56489 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -3096,7 +3096,7 @@
 	    {
 		if (au_has_group((char_u *)"filetypedetect"))
 		    (void)do_doautocmd((char_u *)"filetypedetect BufRead",
-									TRUE);
+								  TRUE, NULL);
 		do_modelines(0);
 	    }