===================================================================
RCS file: /cvs/mandoc/eqn.c,v
retrieving revision 1.42
retrieving revision 1.46
diff -u -p -r1.42 -r1.46
--- mandoc/eqn.c	2014/04/23 21:06:41	1.42
+++ mandoc/eqn.c	2014/09/28 11:32:08	1.46
@@ -1,4 +1,4 @@
-/*	$Id: eqn.c,v 1.42 2014/04/23 21:06:41 schwarze Exp $ */
+/*	$Id: eqn.c,v 1.46 2014/09/28 11:32:08 kristaps Exp $ */
 /*
  * Copyright (c) 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -14,10 +14,10 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
-#ifdef HAVE_CONFIG_H
 #include "config.h"
-#endif
 
+#include <sys/types.h>
+
 #include <assert.h>
 #include <limits.h>
 #include <stdio.h>
@@ -198,6 +198,7 @@ static	const struct eqnstr eqnposs[EQNPOS__MAX] = {
 	{ "", 0 }, /* EQNPOS_NONE */
 	{ "over", 4 }, /* EQNPOS_OVER */
 	{ "sup", 3 }, /* EQNPOS_SUP */
+	{ NULL, 0 }, /* EQNPOS_SUPSUB */
 	{ "sub", 3 }, /* EQNPOS_SUB */
 	{ "to", 2 }, /* EQNPOS_TO */
 	{ "from", 4 }, /* EQNPOS_FROM */
@@ -300,7 +301,8 @@ eqn_read(struct eqn_node **epp, int ln,
 			p++;
 		if ('\0' == *p)
 			return(er);
-		mandoc_msg(MANDOCERR_ARGSLOST, ep->parse, ln, pos, NULL);
+		mandoc_vmsg(MANDOCERR_ARG_SKIP, ep->parse,
+		    ln, pos, "EN %s", p);
 		return(er);
 	}
 
@@ -568,14 +570,30 @@ eqn_box(struct eqn_node *ep, struct eqn_box *last)
 		return(EQN_OK);
 	}
 
+	/*
+	 * Positional elements (e.g., over, sub, sup, ...).
+	 */
 	for (i = 0; i < (int)EQNPOS__MAX; i++) {
-		if ( ! EQNSTREQ(&eqnposs[i], start, sz))
+		/* Some elements don't have names (are virtual). */
+		if (NULL == eqnposs[i].name)
 			continue;
+		else if ( ! EQNSTREQ(&eqnposs[i], start, sz))
+			continue;
 		if (NULL == last->last) {
 			EQN_MSG(MANDOCERR_EQNSYNT, ep);
 			return(EQN_ERR);
 		}
-		last->last->pos = (enum eqn_post)i;
+		/*
+		 * If we encounter x sub y sup z, then according to the
+		 * eqn manual, we regard this as x subsup y z.
+		 */
+		if (EQNPOS_SUP == i &&
+			NULL != last->last->prev &&
+			EQNPOS_SUB == last->last->prev->pos)
+			last->last->prev->pos = EQNPOS_SUBSUP;
+		else
+			last->last->pos = (enum eqn_post)i;
+
 		if (EQN_EOF == (c = eqn_box(ep, last))) {
 			EQN_MSG(MANDOCERR_EQNEOF, ep);
 			return(EQN_ERR);
@@ -664,10 +682,11 @@ eqn_box_alloc(struct eqn_node *ep, struct eqn_box *par
 	bp->parent = parent;
 	bp->size = ep->gsize;
 
-	if (NULL == parent->first)
-		parent->first = bp;
-	else
+	if (NULL != parent->first) {
 		parent->last->next = bp;
+		bp->prev = parent->last;
+	} else
+		parent->first = bp;
 
 	parent->last = bp;
 	return(bp);
@@ -767,7 +786,7 @@ again:
 			ep->cur++;
 	} else {
 		if (q)
-			EQN_MSG(MANDOCERR_BADQUOTE, ep);
+			EQN_MSG(MANDOCERR_ARG_QUOTE, ep);
 		next = strchr(start, '\0');
 		*sz = (size_t)(next - start);
 		ep->cur += *sz;