Rudimentary implementation of the roff(7) \o escape sequence (overstrike).

This is of some relevance because the pod2man(1) preamble abuses it
for the icelandic letter Thorn, instead of simply using \(TP and \(Tp.
Missing feature found by sthen@ in DateTime::Locale::is_IS(3p).

4 files changed, 46 insertions, 11 deletions

diff --git a/usr.bin/mandoc/html.c b/usr.bin/mandoc/html.c
index 69f907ff526..44933c30fae 100644
--- a/usr.bin/mandoc/html.c
+++ b/usr.bin/mandoc/html.c
@@ -1,7 +1,7 @@
-/*	$OpenBSD: html.c,v 1.54 2014/12/20 00:19:54 schwarze Exp $ */
+/*	$OpenBSD: html.c,v 1.55 2015/01/21 20:20:49 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2011, 2012, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2011-2015 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -305,6 +305,8 @@ html_strlen(const char *cp)
 		case ESCAPE_NUMBERED:
 			/* FALLTHROUGH */
 		case ESCAPE_SPECIAL:
+			/* FALLTHROUGH */
+		case ESCAPE_OVERSTRIKE:
 			if (skip)
 				skip = 0;
 			else
@@ -431,6 +433,11 @@ print_encode(struct html *h, const char *p, int norecurse)
 			if ('\0' == *p)
 				nospace = 1;
 			continue;
+		case ESCAPE_OVERSTRIKE:
+			if (len == 0)
+				continue;
+			c = seq[len - 1];
+			break;
 		default:
 			continue;
 		}
diff --git a/usr.bin/mandoc/mandoc.c b/usr.bin/mandoc/mandoc.c
index 362edb9a724..14fd071dbd3 100644
--- a/usr.bin/mandoc/mandoc.c
+++ b/usr.bin/mandoc/mandoc.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mandoc.c,v 1.58 2015/01/01 18:10:09 schwarze Exp $ */
+/*	$OpenBSD: mandoc.c,v 1.59 2015/01/21 20:20:49 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011-2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -154,16 +154,18 @@ mandoc_escape(const char **end, const char **start, int *sz)
 		/* FALLTHROUGH */
 	case 'D':
 		/* FALLTHROUGH */
-	case 'o':
-		/* FALLTHROUGH */
 	case 'R':
 		/* FALLTHROUGH */
 	case 'X':
 		/* FALLTHROUGH */
 	case 'Z':
-		if ('\0' == **start)
-			return(ESCAPE_ERROR);
 		gly = ESCAPE_IGNORE;
+		/* FALLTHROUGH */
+	case 'o':
+		if (**start == '\0')
+			return(ESCAPE_ERROR);
+		if (gly == ESCAPE_ERROR)
+			gly = ESCAPE_OVERSTRIKE;
 		term = **start;
 		*start = ++*end;
 		break;
diff --git a/usr.bin/mandoc/mandoc.h b/usr.bin/mandoc/mandoc.h
index 713bafd7d01..fb255d083af 100644
--- a/usr.bin/mandoc/mandoc.h
+++ b/usr.bin/mandoc/mandoc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mandoc.h,v 1.125 2015/01/20 21:12:46 schwarze Exp $ */
+/*	$OpenBSD: mandoc.h,v 1.126 2015/01/21 20:20:49 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -399,7 +399,8 @@ enum	mandoc_esc {
 	ESCAPE_NUMBERED, /* a numbered glyph */
 	ESCAPE_UNICODE, /* a unicode codepoint */
 	ESCAPE_NOSPACE, /* suppress space if the last on a line */
-	ESCAPE_SKIPCHAR /* skip the next character */
+	ESCAPE_SKIPCHAR, /* skip the next character */
+	ESCAPE_OVERSTRIKE /* overstrike all chars in the argument */
 };
 
 typedef	void	(*mandocmsg)(enum mandocerr, enum mandoclevel,
diff --git a/usr.bin/mandoc/term.c b/usr.bin/mandoc/term.c
index ee247461963..74401b36739 100644
--- a/usr.bin/mandoc/term.c
+++ b/usr.bin/mandoc/term.c
@@ -1,7 +1,7 @@
-/*	$OpenBSD: term.c,v 1.102 2014/12/24 23:31:59 schwarze Exp $ */
+/*	$OpenBSD: term.c,v 1.103 2015/01/21 20:20:49 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2010-2014 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010-2015 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -493,6 +493,17 @@ term_word(struct termp *p, const char *word)
 		case ESCAPE_SKIPCHAR:
 			p->flags |= TERMP_SKIPCHAR;
 			continue;
+		case ESCAPE_OVERSTRIKE:
+			cp = seq + sz;
+			while (seq < cp) {
+				if (*seq == '\\') {
+					mandoc_escape(&seq, NULL, NULL);
+					continue;
+				}
+				encode1(p, *seq++);
+				if (seq < cp)
+					encode(p, "\b", 1);
+			}
 		default:
 			continue;
 		}
@@ -714,6 +725,20 @@ term_strlen(const struct termp *p, const char *cp)
 			case ESCAPE_SKIPCHAR:
 				skip = 1;
 				continue;
+			case ESCAPE_OVERSTRIKE:
+				rsz = 0;
+				rhs = seq + ssz;
+				while (seq < rhs) {
+					if (*seq == '\\') {
+						mandoc_escape(&seq, NULL, NULL);
+						continue;
+					}
+					i = (*p->width)(p, *seq++);
+					if (rsz < i)
+						rsz = i;
+				}
+				sz += rsz;
+				continue;
 			default:
 				continue;
 			}