When calculating string lengths, resolve escape sequences and use

their actual lengths.  Will improve vertical alignment in some
uncommon situations, for example when escape sequences occur in
list or column width strings or in .Nm block arguments in the SYNOPSIS.
From kristaps@.

2 files changed, 50 insertions, 10 deletions

diff --git a/usr.bin/mandoc/man_term.c b/usr.bin/mandoc/man_term.c
index 9c3389d9b1f..074c3b7d257 100644
--- a/usr.bin/mandoc/man_term.c
+++ b/usr.bin/mandoc/man_term.c
@@ -1,4 +1,4 @@
-/*	$Id: man_term.c,v 1.45 2010/07/25 18:05:54 schwarze Exp $ */
+/*	$Id: man_term.c,v 1.46 2010/09/21 22:33:41 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -912,6 +912,10 @@ print_man_foot(struct termp *p, const void *arg)
 	p->rmargin = p->maxrmargin - term_strlen(p, buf);
 	p->offset = 0;
 
+	/* term_strlen() can return zero. */
+	if (p->rmargin == p->maxrmargin)
+		p->rmargin--;
+
 	if (meta->source)
 		term_word(p, meta->source);
 	if (meta->source)
diff --git a/usr.bin/mandoc/term.c b/usr.bin/mandoc/term.c
index 4f307967d9b..c0a8918184a 100644
--- a/usr.bin/mandoc/term.c
+++ b/usr.bin/mandoc/term.c
@@ -1,4 +1,4 @@
-/*	$Id: term.c,v 1.49 2010/08/20 23:34:00 schwarze Exp $ */
+/*	$Id: term.c,v 1.50 2010/09/21 22:33:41 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010 Ingo Schwarze <schwarze@openbsd.org>
@@ -79,7 +79,7 @@ term_alloc(enum termenc enc)
 	p = calloc(1, sizeof(struct termp));
 	if (NULL == p) {
 		perror(NULL);
-		exit(MANDOCLEVEL_SYSERR);
+		exit((int)MANDOCLEVEL_SYSERR);
 	}
 
 	p->enc = enc;
@@ -454,7 +454,6 @@ void
 term_word(struct termp *p, const char *word)
 {
 	const char	*sv, *seq;
-	int		 sz;
 	size_t		 ssz;
 	enum roffdeco	 deco;
 
@@ -511,7 +510,7 @@ term_word(struct termp *p, const char *word)
 			continue;
 
 		seq = ++word;
-		sz = a2roffdeco(&deco, &seq, &ssz);
+		word += a2roffdeco(&deco, &seq, &ssz);
 
 		switch (deco) {
 		case (DECO_RESERVED):
@@ -538,7 +537,6 @@ term_word(struct termp *p, const char *word)
 			break;
 		}
 
-		word += sz;
 		if (DECO_NOSPACE == deco && '\0' == *word)
 			p->flags |= TERMP_NOSPACE;
 	}
@@ -572,7 +570,7 @@ adjbuf(struct termp *p, size_t sz)
 	p->buf = realloc(p->buf, p->maxcols);
 	if (NULL == p->buf) {
 		perror(NULL);
-		exit(MANDOCLEVEL_SYSERR);
+		exit((int)MANDOCLEVEL_SYSERR);
 	}
 }
 
@@ -641,10 +639,48 @@ term_len(const struct termp *p, size_t sz)
 size_t
 term_strlen(const struct termp *p, const char *cp)
 {
-	size_t		 sz;
+	size_t		 sz, ssz, rsz, i;
+	enum roffdeco	 d;
+	const char	*seq, *rhs;
 
-	for (sz = 0; *cp; cp++)
-		sz += (*p->width)(p, *cp);
+	for (sz = 0; '\0' != *cp; )
+		/*
+		 * Account for escaped sequences within string length
+		 * calculations.  This follows the logic in term_word()
+		 * as we must calculate the width of produced strings.
+		 */
+		if ('\\' == *cp) {
+			seq = ++cp;
+			cp += a2roffdeco(&d, &seq, &ssz);
+
+			switch (d) {
+			case (DECO_RESERVED):
+				rhs = chars_res2str
+					(p->symtab, seq, ssz, &rsz);
+				break;
+			case (DECO_SPECIAL):
+				/* FALLTHROUGH */
+			case (DECO_SSPECIAL):
+				rhs = chars_spec2str
+					(p->symtab, seq, ssz, &rsz);
+
+				/* Allow for one-char escapes. */
+				if (DECO_SSPECIAL != d || rhs)
+					break;
+
+				rhs = seq;
+				rsz = ssz;
+				break;
+			default:
+				rhs = NULL;
+				break;
+			}
+
+			if (rhs)
+				for (i = 0; i < rsz; i++)
+					sz += (*p->width)(p, *rhs++);
+		} else
+			sz += (*p->width)(p, *cp++);
 
 	return(sz);
 }