Minimal implementation of the \h (horizontal motion) escape sequence.

Good enough to cope with the average DocBook insanity.

6 files changed, 38 insertions, 13 deletions

diff --git a/mandoc.c b/mandoc.c
index d265463b..2ff4e186 100644
--- a/mandoc.c
+++ b/mandoc.c
@@ -1,4 +1,4 @@
-/*	$Id: mandoc.c,v 1.98 2015/11/12 22:44:27 schwarze Exp $ */
+/*	$Id: mandoc.c,v 1.99 2017/06/01 19:05:37 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011-2015 Ingo Schwarze <schwarze@openbsd.org>
@@ -175,7 +175,7 @@ mandoc_escape(const char **end, const char **start, int *sz)
 				++*end;
 			return ESCAPE_ERROR;
 		}
-		gly = ESCAPE_IGNORE;
+		gly = (*start)[-1] == 'h' ? ESCAPE_HORIZ : ESCAPE_IGNORE;
 		term = **start;
 		*start = ++*end;
 		break;
diff --git a/mandoc.h b/mandoc.h
index f18d2d12..c15ed4d0 100644
--- a/mandoc.h
+++ b/mandoc.h
@@ -1,4 +1,4 @@
-/*	$Id: mandoc.h,v 1.219 2017/06/01 15:25:39 schwarze Exp $ */
+/*	$Id: mandoc.h,v 1.220 2017/06/01 19:05:37 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2011, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -411,6 +411,7 @@ enum	mandoc_esc {
 	ESCAPE_NUMBERED, /* a numbered glyph */
 	ESCAPE_UNICODE, /* a unicode codepoint */
 	ESCAPE_NOSPACE, /* suppress space if the last on a line */
+	ESCAPE_HORIZ, /* horizontal movement */
 	ESCAPE_SKIPCHAR, /* skip the next character */
 	ESCAPE_OVERSTRIKE /* overstrike all chars in the argument */
 };
diff --git a/mdoc_term.c b/mdoc_term.c
index 382804d5..77bb6be2 100644
--- a/mdoc_term.c
+++ b/mdoc_term.c
@@ -1,4 +1,4 @@
-/*	$Id: mdoc_term.c,v 1.358 2017/05/30 16:31:29 schwarze Exp $ */
+/*	$Id: mdoc_term.c,v 1.359 2017/06/01 19:05:37 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010, 2012-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -407,7 +407,8 @@ print_mdoc_node(DECL_ARGS)
 	if (NODE_EOS & n->flags)
 		p->flags |= TERMP_SENTENCE;
 
-	p->offset = offset;
+	if (n->type != ROFFT_TEXT)
+		p->offset = offset;
 	p->rmargin = rmargin;
 }
 
diff --git a/regress/roff/esc/h.in b/regress/roff/esc/h.in
index 31fbb4e2..4bc1953e 100644
--- a/regress/roff/esc/h.in
+++ b/regress/roff/esc/h.in
@@ -7,11 +7,11 @@
 .Sh DESCRIPTION
 simple: >\h'0'<
 .br
-escape only: >\h'\w'\&''<
+escape only: >\h'\w'\&'M'<
 .br
 escape at the end: >\h'0+\w'\&''<
 .br
-escape at the beginning: >\h'\w'\&'+0'<
+escape at the beginning: >\h'\w'\&'M+0'<
 .br
 escape in the middle: >\h'0+\w'\&'+0'<
 .br
diff --git a/roff.7 b/roff.7
index b6876e35..bfce9b16 100644
--- a/roff.7
+++ b/roff.7
@@ -1,4 +1,4 @@
-.\"	$Id: roff.7,v 1.80 2017/05/08 15:34:54 schwarze Exp $
+.\"	$Id: roff.7,v 1.81 2017/06/01 19:05:37 schwarze Exp $
 .\"
 .\" Copyright (c) 2010, 2011, 2012 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2010,2011,2013-2015,2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: May 8 2017 $
+.Dd $Mdocdate: June 1 2017 $
 .Dt ROFF 7
 .Os
 .Sh NAME
@@ -1925,9 +1925,10 @@ and
 .Ss \eH\(aq Ns Oo +|- Oc Ns Ar number Ns \(aq
 Set the height of the current font; ignored by
 .Xr mandoc 1 .
-.Ss \eh\(aq Ns Ar number Ns \(aq
-Horizontal motion; ignored by
-.Xr mandoc 1 .
+.Ss \eh\(aq Ns Ar width Ns \(aq
+Horizontal motion relative to the current position.
+The default scaling unit is
+.Cm m .
 .Ss \ek[ Ns Ar name ]
 Mark horizontal input place in register; ignored by
 .Xr mandoc 1 .
diff --git a/term.c b/term.c
index f2553d89..266c49e7 100644
--- a/term.c
+++ b/term.c
@@ -1,4 +1,4 @@
-/*	$Id: term.c,v 1.260 2017/05/07 17:31:45 schwarze Exp $ */
+/*	$Id: term.c,v 1.261 2017/06/01 19:05:37 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -400,6 +400,7 @@ term_fontpop(struct termp *p)
 void
 term_word(struct termp *p, const char *word)
 {
+	struct roffsu	 su;
 	const char	 nbrsp[2] = { ASCII_NBRSP, 0 };
 	const char	*seq, *cp;
 	int		 sz, uc;
@@ -488,6 +489,27 @@ term_word(struct termp *p, const char *word)
 			else if (*word == '\0')
 				p->flags |= (TERMP_NOSPACE | TERMP_NONEWLINE);
 			continue;
+		case ESCAPE_HORIZ:
+			if (a2roffsu(seq, &su, SCALE_EM) == 0)
+				continue;
+			uc = term_hspan(p, &su) / 24;
+			if (uc > 0)
+				while (uc-- > 0)
+					bufferc(p, ASCII_NBRSP);
+			else if (p->col > (size_t)(-uc))
+				p->col += uc;
+			else {
+				uc += p->col;
+				p->col = 0;
+				if (p->offset > (size_t)(-uc)) {
+					p->ti += uc;
+					p->offset += uc;
+				} else {
+					p->ti -= p->offset;
+					p->offset = 0;
+				}
+			}
+			continue;
 		case ESCAPE_SKIPCHAR:
 			p->flags |= TERMP_BACKAFTER;
 			continue;