===================================================================
RCS file: /cvs/mandoc/mdoc_validate.c,v
retrieving revision 1.60
retrieving revision 1.61
diff -u -p -r1.60 -r1.61
--- mandoc/mdoc_validate.c	2010/04/03 13:02:35	1.60
+++ mandoc/mdoc_validate.c	2010/04/03 14:02:10	1.61
@@ -1,4 +1,4 @@
-/*	$Id: mdoc_validate.c,v 1.60 2010/04/03 13:02:35 kristaps Exp $ */
+/*	$Id: mdoc_validate.c,v 1.61 2010/04/03 14:02:10 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -621,8 +621,19 @@ pre_bl(PRE_ARGS)
 		case (MDOC_Inset):
 			/* FALLTHROUGH */
 		case (MDOC_Column):
-			if (type >= 0) 
-				return(mdoc_nerr(mdoc, n, EMULTILIST));
+			/*
+			 * Note that if a duplicate is detected, we
+			 * remove the duplicate instead of passing it
+			 * over.  If we don't do this, mdoc_action will
+			 * become confused when it scans over multiple
+			 * types whilst setting its bitmasks.
+			 */
+			if (type >= 0) {
+				if ( ! mdoc_nwarn(mdoc, n, EMULTILIST))
+					return(0);
+				mdoc_argn_free(n->args, pos);
+				break;
+			}
 			type = n->args->argv[pos].arg;
 			break;
 		case (MDOC_Compact):