===================================================================
RCS file: /cvs/mandoc/roff.c,v
retrieving revision 1.185
retrieving revision 1.188
diff -u -p -r1.185 -r1.188
--- mandoc/roff.c	2013/10/14 01:43:14	1.185
+++ mandoc/roff.c	2013/12/25 00:50:05	1.188
@@ -1,4 +1,4 @@
-/*	$Id: roff.c,v 1.185 2013/10/14 01:43:14 schwarze Exp $ */
+/*	$Id: roff.c,v 1.188 2013/12/25 00:50:05 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010, 2011, 2012, 2013 Ingo Schwarze <schwarze@openbsd.org>
@@ -47,6 +47,7 @@ enum	rofft {
 	ROFF_ds,
 	ROFF_el,
 	ROFF_fam,
+	ROFF_hw,
 	ROFF_hy,
 	ROFF_ie,
 	ROFF_if,
@@ -237,6 +238,7 @@ static	struct roffmac	 roffs[ROFF_MAX] = {
 	{ "ds", roff_ds, NULL, NULL, 0, NULL },
 	{ "el", roff_cond, roff_cond_text, roff_cond_sub, ROFFMAC_STRUCT, NULL },
 	{ "fam", roff_line_ignore, NULL, NULL, 0, NULL },
+	{ "hw", roff_line_ignore, NULL, NULL, 0, NULL },
 	{ "hy", roff_line_ignore, NULL, NULL, 0, NULL },
 	{ "ie", roff_cond, roff_cond_text, roff_cond_sub, ROFFMAC_STRUCT, NULL },
 	{ "if", roff_cond, roff_cond_text, roff_cond_sub, ROFFMAC_STRUCT, NULL },
@@ -1358,7 +1360,7 @@ roff_ds(ROFF_ARGS)
 }
 
 void
-roff_setreg(struct roff *r, const char *name, int val)
+roff_setreg(struct roff *r, const char *name, int val, char sign)
 {
 	struct roffreg	*reg;
 
@@ -1373,11 +1375,17 @@ roff_setreg(struct roff *r, const char *name, int val)
 		reg = mandoc_malloc(sizeof(struct roffreg));
 		reg->key.p = mandoc_strdup(name);
 		reg->key.sz = strlen(name);
+		reg->val = 0;
 		reg->next = r->regtab;
 		r->regtab = reg;
 	}
 
-	reg->val = val;
+	if ('+' == sign)
+		reg->val += val;
+	else if ('-' == sign)
+		reg->val -= val;
+	else
+		reg->val = val;
 }
 
 int
@@ -1424,15 +1432,22 @@ roff_nr(ROFF_ARGS)
 {
 	const char	*key;
 	char		*val;
+	size_t		 sz;
 	int		 iv;
+	char		 sign;
 
 	val = *bufp + pos;
 	key = roff_getname(r, &val, ln, pos);
 
-	iv = mandoc_strntoi(val, strlen(val), 10);
+	sign = *val;
+	if ('+' == sign || '-' == sign)
+		val++;
 
-	roff_setreg(r, key, iv);
+	sz = strspn(val, "0123456789");
+	iv = sz ? mandoc_strntoi(val, sz, 10) : 0;
 
+	roff_setreg(r, key, iv, sign);
+
 	return(ROFF_IGN);
 }
 
@@ -1718,7 +1733,7 @@ roff_userdef(ROFF_ARGS)
 
 	/*
 	 * Collect pointers to macro argument strings
-	 * and null-terminate them.
+	 * and NUL-terminate them.
 	 */
 	cp = *bufp + pos;
 	for (i = 0; i < 9; i++)