===================================================================
RCS file: /cvs/mandoc/tbl_data.c,v
retrieving revision 1.17
retrieving revision 1.19
diff -u -p -r1.17 -r1.19
--- mandoc/tbl_data.c	2011/01/10 14:56:06	1.17
+++ mandoc/tbl_data.c	2011/01/11 14:12:01	1.19
@@ -1,4 +1,4 @@
-/*	$Id: tbl_data.c,v 1.17 2011/01/10 14:56:06 kristaps Exp $ */
+/*	$Id: tbl_data.c,v 1.19 2011/01/11 14:12:01 kristaps Exp $ */
 /*
  * Copyright (c) 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -122,7 +122,8 @@ data(struct tbl_node *tbl, struct tbl_span *dp, 
 		dat->pos = TBL_DATA_DATA;
 
 	if (TBL_CELL_HORIZ == dat->layout->pos ||
-			TBL_CELL_DHORIZ == dat->layout->pos)
+			TBL_CELL_DHORIZ == dat->layout->pos ||
+			TBL_CELL_DOWN == dat->layout->pos)
 		if (TBL_DATA_DATA == dat->pos && '\0' != *dat->string)
 			TBL_MSG(tbl, MANDOCERR_TBLIGNDATA, ln, sv);
 
@@ -165,6 +166,9 @@ tbl_cdata(struct tbl_node *tbl, int ln, const char *p)
 	} else
 		dat->string = mandoc_strdup(p);
 
+	if (TBL_CELL_DOWN == dat->layout->pos) 
+		TBL_MSG(tbl, MANDOCERR_TBLIGNDATA, ln, pos);
+
 	return(0);
 }
 
@@ -188,8 +192,6 @@ tbl_data(struct tbl_node *tbl, int ln, const char *p)
 	 * If there's no last parsed span, use the first row.  Lastly,
 	 * if the last span was a horizontal line, use the same layout
 	 * (it doesn't "consume" the layout).
-	 *
-	 * In the end, this can be NULL!
 	 */
 
 	if (tbl->last_span) {
@@ -198,10 +200,13 @@ tbl_data(struct tbl_node *tbl, int ln, const char *p)
 			rp = tbl->last_span->layout->next;
 		else
 			rp = tbl->last_span->layout;
+
 		if (NULL == rp)
 			rp = tbl->last_span->layout;
 	} else
 		rp = tbl->first_row;
+
+	assert(rp);
 
 	dp = mandoc_calloc(1, sizeof(struct tbl_span));
 	dp->tbl = &tbl->opts;