patch 7.4.1728
Problem:    The help for functions require a space after the "(".
Solution:   Make CTRL-] on a function name ignore the arguments. (Hirohito
            Higashi)
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index daac3ae..d83dc40 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -6204,6 +6204,13 @@
 	    *d++ = *s;
 
 	    /*
+	     * If tag contains "({" or "([", tag terminates at the "(".
+	     * This is for help on functions, e.g.: abs({expr}).
+	     */
+	    if (*s == '(' && (s[1] == '{' || s[1] =='['))
+		break;
+
+	    /*
 	     * If tag starts with ', toss everything after a second '. Fixes
 	     * CTRL-] on 'option'. (would include the trailing '.').
 	     */