===================================================================
RCS file: /cvs/mandoc/term.c,v
retrieving revision 1.287
retrieving revision 1.289
diff -u -p -r1.287 -r1.289
--- mandoc/term.c	2022/08/15 10:22:14	1.287
+++ mandoc/term.c	2022/08/15 18:12:30	1.289
@@ -1,4 +1,4 @@
-/* $Id: term.c,v 1.287 2022/08/15 10:22:14 schwarze Exp $ */
+/* $Id: term.c,v 1.289 2022/08/15 18:12:30 schwarze Exp $ */
 /*
  * Copyright (c) 2010-2022 Ingo Schwarze <schwarze@openbsd.org>
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
@@ -157,6 +157,7 @@ term_flushln(struct termp *p)
 		/* Finally, print the field content. */
 
 		term_field(p, vbl, nbr);
+		p->tcol->taboff += vbr + (*p->width)(p, ' ');
 
 		/*
 		 * If there is no text left in the field, exit the loop.
@@ -207,7 +208,6 @@ term_flushln(struct termp *p)
 			return;
 
 		endline(p);
-		p->viscol = 0;
 
 		/*
 		 * Normally, start the next line at the same indentation
@@ -309,8 +309,12 @@ term_fill(struct termp *p, size_t *nbr, size_t *vbr, s
 		default:
 			switch (p->tcol->buf[ic]) {
 			case '\t':
+				vis += p->tcol->taboff;
 				vis = term_tab_next(vis);
+				vis -= p->tcol->taboff;
 				break;
+			case ASCII_NBRZW:  /* Non-breakable zero-width. */
+				break;
 			case ASCII_NBRSP:  /* Non-breakable space. */
 				p->tcol->buf[ic] = ' ';
 				/* FALLTHROUGH */
@@ -348,8 +352,8 @@ term_field(struct termp *p, size_t vbl, size_t nbr)
 {
 	size_t	 ic;	/* Character position in the input buffer. */
 	size_t	 vis;	/* Visual position of the current character. */
+	size_t	 vt;	/* Visual position including tab offset. */
 	size_t	 dv;	/* Visual width of the current character. */
-	size_t	 vn;	/* Visual position of the next character. */
 
 	vis = 0;
 	for (ic = p->tcol->col; ic < nbr; ic++) {
@@ -362,15 +366,16 @@ term_field(struct termp *p, size_t vbl, size_t nbr)
 		switch (p->tcol->buf[ic]) {
 		case '\n':
 		case ASCII_BREAK:
+		case ASCII_NBRZW:
 			continue;
 		case '\t':
-			vn = term_tab_next(vis);
-			vbl += vn - vis;
-			vis = vn;
-			continue;
 		case ' ':
 		case ASCII_NBRSP:
-			dv = (*p->width)(p, ' ');
+			if (p->tcol->buf[ic] == '\t') {
+				vt = p->tcol->taboff + vis;
+				dv = term_tab_next(vt) - vt;
+			} else
+				dv = (*p->width)(p, ' ');
 			vbl += dv;
 			vis += dv;
 			continue;
@@ -432,7 +437,7 @@ endline(struct termp *p)
 void
 term_newln(struct termp *p)
 {
-
+	p->tcol->taboff = 0;
 	p->flags |= TERMP_NOSPACE;
 	if (p->tcol->lastcol || p->viscol)
 		term_flushln(p);
@@ -568,18 +573,23 @@ term_word(struct termp *p, const char *word)
 			break;
 		case ESCAPE_NUMBERED:
 			uc = mchars_num2char(seq, sz);
-			if (uc < 0)
-				continue;
-			break;
+			if (uc >= 0)
+				break;
+			bufferc(p, ASCII_NBRZW);
+			continue;
 		case ESCAPE_SPECIAL:
 			if (p->enc == TERMENC_ASCII) {
 				cp = mchars_spec2str(seq, sz, &ssz);
 				if (cp != NULL)
 					encode(p, cp, ssz);
+				else
+					bufferc(p, ASCII_NBRZW);
 			} else {
 				uc = mchars_spec2cp(seq, sz);
 				if (uc > 0)
 					encode1(p, uc);
+				else
+					bufferc(p, ASCII_NBRZW);
 			}
 			continue;
 		case ESCAPE_UNDEF:
@@ -741,6 +751,9 @@ term_word(struct termp *p, const char *word)
 			if (p->col > p->tcol->lastcol)
 				p->col = p->tcol->lastcol;
 			continue;
+		case ESCAPE_IGNORE:
+			bufferc(p, ASCII_NBRZW);
+			continue;
 		default:
 			continue;
 		}
@@ -932,8 +945,8 @@ term_strlen(const struct termp *p, const char *cp)
 	int		 ssz, skip, uc;
 	const char	*seq, *rhs;
 	enum mandoc_esc	 esc;
-	static const char rej[] = { '\\', ASCII_NBRSP, ASCII_HYPH,
-			ASCII_BREAK, '\0' };
+	static const char rej[] = { '\\', ASCII_NBRSP, ASCII_NBRZW,
+		ASCII_BREAK, ASCII_HYPH, '\0' };
 
 	/*
 	 * Account for escaped sequences within string length