patch 7.4.1568
Problem:    Using CTRL-] in help on option in parentheses doesn't work.
Solution:   Skip the "(" in "('". (Hirohito Higashi)
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index b743477..6461c3c 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -6114,6 +6114,11 @@
 		    || (arg[0] == '\\' && arg[1] == '{'))
 	      *d++ = '\\';
 
+	  /*
+	   * If tag starts with "('", skip the "(". Fixes CTRL-] on ('option'.
+	   */
+	  if (*arg == '(' && arg[1] == '\'')
+	      arg++;
 	  for (s = arg; *s; ++s)
 	  {
 	    /*