Implement the roff(7) .mc (right margin character) request.

The Tcl/Tk manual pages use this extensively.
Delete the TERM_MAXMARGIN hack, it breaks .mc inside .nf;
instead, implement a proper TERMP_BRNEVER flag.

12 files changed, 119 insertions, 101 deletions

diff --git a/man_term.c b/man_term.c
index b86af98f..8a047d8b 100644
--- a/man_term.c
+++ b/man_term.c
@@ -862,7 +862,6 @@ post_UR(DECL_ARGS)
 static void
 print_man_node(DECL_ARGS)
 {
-	size_t		 rm, rmax;
 	int		 c;
 
 	switch (n->type) {
@@ -930,20 +929,16 @@ out:
 	if (mt->fl & MANT_LITERAL &&
 	    ! (p->flags & (TERMP_NOBREAK | TERMP_NONEWLINE)) &&
 	    (n->next == NULL || n->next->flags & NODE_LINE)) {
-		rm = p->rmargin;
-		rmax = p->maxrmargin;
-		p->rmargin = p->maxrmargin = TERM_MAXMARGIN;
-		p->flags |= TERMP_NOSPACE;
+		p->flags |= TERMP_BRNEVER | TERMP_NOSPACE;
 		if (n->string != NULL && *n->string != '\0')
 			term_flushln(p);
 		else
 			term_newln(p);
-		if (rm < rmax && n->parent->tok == MAN_HP) {
-			p->offset = rm;
-			p->rmargin = rmax;
-		} else
-			p->rmargin = rm;
-		p->maxrmargin = rmax;
+		p->flags &= ~TERMP_BRNEVER;
+		if (p->rmargin < p->maxrmargin && n->parent->tok == MAN_HP) {
+			p->offset = p->rmargin;
+			p->rmargin = p->maxrmargin;
+		}
 	}
 	if (NODE_EOS & n->flags)
 		p->flags |= TERMP_SENTENCE;
diff --git a/mdoc_man.c b/mdoc_man.c
index 3bd059c0..26293214 100644
--- a/mdoc_man.c
+++ b/mdoc_man.c
@@ -128,6 +128,7 @@ static	const void_fp roff_manacts[ROFF_MAX] = {
 	pre_br,
 	pre_ft,
 	pre_onearg,
+	pre_onearg,
 	pre_sp,
 	pre_ta,
 	pre_onearg,
diff --git a/mdoc_term.c b/mdoc_term.c
index 26ddbea1..ed462d61 100644
--- a/mdoc_term.c
+++ b/mdoc_term.c
@@ -1413,7 +1413,7 @@ termp_fa_pre(DECL_ARGS)
 static int
 termp_bd_pre(DECL_ARGS)
 {
-	size_t			 lm, len, rm, rmax;
+	size_t			 lm, len;
 	struct roff_node	*nn;
 	int			 offset;
 
@@ -1460,17 +1460,14 @@ termp_bd_pre(DECL_ARGS)
 	}
 
 	lm = p->offset;
-	rm = p->rmargin;
-	rmax = p->maxrmargin;
-	p->rmargin = p->maxrmargin = TERM_MAXMARGIN;
-
+	p->flags |= TERMP_BRNEVER;
 	for (nn = n->child; nn; nn = nn->next) {
 		if (DISP_centered == n->norm->Bd.type) {
 			if (nn->type == ROFFT_TEXT) {
 				len = term_strlen(p, nn->string);
-				p->offset = len >= rm ? 0 :
-				    lm + len >= rm ? rm - len :
-				    (lm + rm - len) / 2;
+				p->offset = len >= p->rmargin ? 0 :
+				    lm + len >= p->rmargin ? p->rmargin - len :
+				    (lm + p->rmargin - len) / 2;
 			} else
 				p->offset = lm;
 		}
@@ -1500,32 +1497,21 @@ termp_bd_pre(DECL_ARGS)
 		term_flushln(p);
 		p->flags |= TERMP_NOSPACE;
 	}
-
-	p->rmargin = rm;
-	p->maxrmargin = rmax;
+	p->flags &= ~TERMP_BRNEVER;
 	return 0;
 }
 
 static void
 termp_bd_post(DECL_ARGS)
 {
-	size_t		 rm, rmax;
-
 	if (n->type != ROFFT_BODY)
 		return;
-
-	rm = p->rmargin;
-	rmax = p->maxrmargin;
-
 	if (DISP_literal == n->norm->Bd.type ||
 	    DISP_unfilled == n->norm->Bd.type)
-		p->rmargin = p->maxrmargin = TERM_MAXMARGIN;
-
+		p->flags |= TERMP_BRNEVER;
 	p->flags |= TERMP_NOSPACE;
 	term_newln(p);
-
-	p->rmargin = rm;
-	p->maxrmargin = rmax;
+	p->flags &= ~TERMP_BRNEVER;
 }
 
 static int
diff --git a/roff.7 b/roff.7
index 86d6cb84..b2e8fb78 100644
--- a/roff.7
+++ b/roff.7
@@ -1296,7 +1296,9 @@ Set title line length.
 Currently ignored.
 .It Ic \&mc Ar glyph Op Ar dist
 Print margin character in the right margin.
-Currently ignored.
+The
+.Ar dist
+is currently ignored; instead, 1n is used.
 .It Ic \&mediasize Ar media
 Set the device media size.
 This is a Heirloom extension and currently ignored.
diff --git a/roff.c b/roff.c
index 83376e90..de3e204c 100644
--- a/roff.c
+++ b/roff.c
@@ -215,8 +215,8 @@ static	enum rofferr	 roff_userdef(ROFF_ARGS);
 #define	ROFFNUM_WHITE	(1 << 1)  /* Skip whitespace in roff_evalnum(). */
 
 const char *__roff_name[MAN_MAX + 1] = {
-	"br",		"ft",		"ll",		"sp",
-	"ta",		"ti",		NULL,
+	"br",		"ft",		"ll",		"mc",
+	"sp",		"ta",		"ti",		NULL,
 	"ab",		"ad",		"af",		"aln",
 	"als",		"am",		"am1",		"ami",
 	"ami1",		"as",		"as1",		"asciify",
@@ -249,7 +249,7 @@ const char *__roff_name[MAN_MAX + 1] = {
 	"lc",		"lc_ctype",	"lds",		"length",
 	"letadj",	"lf",		"lg",		"lhang",
 	"linetabs",	"lnr",		"lnrf",		"lpfx",
-	"ls",		"lsm",		"lt",		"mc",
+	"ls",		"lsm",		"lt",
 	"mediasize",	"minss",	"mk",		"mso",
 	"na",		"ne",		"nh",		"nhychar",
 	"nm",		"nn",		"nop",		"nr",
@@ -325,6 +325,7 @@ static	struct roffmac	 roffs[TOKEN_NONE] = {
 	{ roff_br, NULL, NULL, 0 },  /* br */
 	{ roff_onearg, NULL, NULL, 0 },  /* ft */
 	{ roff_onearg, NULL, NULL, 0 },  /* ll */
+	{ roff_onearg, NULL, NULL, 0 },  /* mc */
 	{ roff_onearg, NULL, NULL, 0 },  /* sp */
 	{ roff_manyarg, NULL, NULL, 0 },  /* ta */
 	{ roff_onearg, NULL, NULL, 0 },  /* ti */
@@ -460,7 +461,6 @@ static	struct roffmac	 roffs[TOKEN_NONE] = {
 	{ roff_line_ignore, NULL, NULL, 0 },  /* ls */
 	{ roff_unsupp, NULL, NULL, 0 },  /* lsm */
 	{ roff_line_ignore, NULL, NULL, 0 },  /* lt */
-	{ roff_line_ignore, NULL, NULL, 0 },  /* mc */
 	{ roff_line_ignore, NULL, NULL, 0 },  /* mediasize */
 	{ roff_line_ignore, NULL, NULL, 0 },  /* minss */
 	{ roff_line_ignore, NULL, NULL, 0 },  /* mk */
diff --git a/roff.h b/roff.h
index 4fd0fa42..3823490a 100644
--- a/roff.h
+++ b/roff.h
@@ -69,6 +69,7 @@ enum	roff_tok {
 	ROFF_br = 0,
 	ROFF_ft,
 	ROFF_ll,
+	ROFF_mc,
 	ROFF_sp,
 	ROFF_ta,
 	ROFF_ti,
@@ -206,7 +207,6 @@ enum	roff_tok {
 	ROFF_ls,
 	ROFF_lsm,
 	ROFF_lt,
-	ROFF_mc,
 	ROFF_mediasize,
 	ROFF_minss,
 	ROFF_mk,
diff --git a/roff_html.c b/roff_html.c
index e76ca544..f04b93c5 100644
--- a/roff_html.c
+++ b/roff_html.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD$ */
+/*	$Id$ */
 /*
  * Copyright (c) 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2014, 2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -35,6 +35,7 @@ static	const roff_html_pre_fp roff_html_pre_acts[ROFF_MAX] = {
 	roff_html_pre_br,  /* br */
 	NULL,  /* ft */
 	NULL,  /* ll */
+	NULL,  /* mc */
 	roff_html_pre_sp,  /* sp */
 	NULL,  /* ta */
 	NULL,  /* ti */
diff --git a/roff_term.c b/roff_term.c
index 3c2f24a9..22af42b0 100644
--- a/roff_term.c
+++ b/roff_term.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD$ */
+/*	$Id$ */
 /*
  * Copyright (c) 2010, 2014, 2015, 2017 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -30,6 +30,7 @@ typedef	void	(*roff_term_pre_fp)(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_br(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ft(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ll(ROFF_TERM_ARGS);
+static	void	  roff_term_pre_mc(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_sp(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ta(ROFF_TERM_ARGS);
 static	void	  roff_term_pre_ti(ROFF_TERM_ARGS);
@@ -37,7 +38,8 @@ static	void	  roff_term_pre_ti(ROFF_TERM_ARGS);
 static	const roff_term_pre_fp roff_term_pre_acts[ROFF_MAX] = {
 	roff_term_pre_br,  /* br */
 	roff_term_pre_ft,  /* ft */
-	roff_term_pre_ll,  /* ft */
+	roff_term_pre_ll,  /* ll */
+	roff_term_pre_mc,  /* mc */
 	roff_term_pre_sp,  /* sp */
 	roff_term_pre_ta,  /* ta */
 	roff_term_pre_ti,  /* ti */
@@ -95,6 +97,21 @@ roff_term_pre_ll(ROFF_TERM_ARGS)
 }
 
 static void
+roff_term_pre_mc(ROFF_TERM_ARGS)
+{
+	if (p->col) {
+		p->flags |= TERMP_NOBREAK;
+		term_flushln(p);
+		p->flags &= ~(TERMP_NOBREAK | TERMP_NOSPACE);
+	}
+	if (n->child != NULL) {
+		p->mc = n->child->string;
+		p->flags |= TERMP_NEWMC;
+	} else
+		p->flags |= TERMP_ENDMC;
+}
+
+static void
 roff_term_pre_sp(ROFF_TERM_ARGS)
 {
 	struct roffsu	 su;
diff --git a/roff_validate.c b/roff_validate.c
index e1ee0ea9..f62544ca 100644
--- a/roff_validate.c
+++ b/roff_validate.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: roff_html.c,v 1.1 2017/05/04 22:07:44 schwarze Exp $ */
+/*	$Id$ */
 /*
  * Copyright (c) 2010, 2017 Ingo Schwarze <schwarze@openbsd.org>
  *
@@ -34,6 +34,7 @@ static	const roff_valid_fp roff_valids[ROFF_MAX] = {
 	NULL,  /* br */
 	roff_valid_ft,  /* ft */
 	NULL,  /* ll */
+	NULL,  /* mc */
 	NULL,  /* sp */
 	NULL,  /* ta */
 	NULL,  /* ti */
diff --git a/tbl_term.c b/tbl_term.c
index ef64a838..c436481b 100644
--- a/tbl_term.c
+++ b/tbl_term.c
@@ -1,7 +1,7 @@
 /*	$Id$ */
 /*
  * Copyright (c) 2009, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2011, 2012, 2014, 2015 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2011,2012,2014,2015,2017 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
@@ -63,18 +63,12 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 	const struct tbl_cell	*cp;
 	const struct tbl_dat	*dp;
 	static size_t		 offset;
-	size_t			 rmargin, maxrmargin, tsz;
+	size_t			 tsz;
 	int			 ic, horiz, spans, vert;
 
-	rmargin = tp->rmargin;
-	maxrmargin = tp->maxrmargin;
-
-	tp->rmargin = tp->maxrmargin = TERM_MAXMARGIN;
-
 	/* Inhibit printing of spaces: we do padding ourselves. */
 
-	tp->flags |= TERMP_NONOSPACE;
-	tp->flags |= TERMP_NOSPACE;
+	tp->flags |= TERMP_NOSPACE | TERMP_NONOSPACE | TERMP_BRNEVER;
 
 	/*
 	 * The first time we're invoked for a given table block,
@@ -86,7 +80,7 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 		tp->tbl.slen = term_tbl_strlen;
 		tp->tbl.arg = tp;
 
-		tblcalc(&tp->tbl, sp, rmargin - tp->offset);
+		tblcalc(&tp->tbl, sp, tp->rmargin - tp->offset);
 
 		/* Center the table as a whole. */
 
@@ -97,10 +91,10 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 			for (ic = 0; ic < sp->opts->cols; ic++)
 				tsz += tp->tbl.cols[ic].width + 3;
 			tsz -= 3;
-			if (offset + tsz > rmargin)
+			if (offset + tsz > tp->rmargin)
 				tsz -= 1;
-			tp->offset = (offset + rmargin > tsz) ?
-			    (offset + rmargin - tsz) / 2 : 0;
+			tp->offset = (offset + tp->rmargin > tsz) ?
+			    (offset + tp->rmargin - tsz) / 2 : 0;
 		}
 
 		/* Horizontal frame at the start of boxed tables. */
@@ -201,10 +195,7 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 		tp->tbl.cols = NULL;
 		tp->offset = offset;
 	}
-
-	tp->flags &= ~TERMP_NONOSPACE;
-	tp->rmargin = rmargin;
-	tp->maxrmargin = maxrmargin;
+	tp->flags &= ~(TERMP_NONOSPACE | TERMP_BRNEVER);
 }
 
 /*
diff --git a/term.c b/term.c
index 0c0fef67..b9bdc9b9 100644
--- a/term.c
+++ b/term.c
@@ -36,6 +36,7 @@ static	void		 adjbuf(struct termp *p, size_t);
 static	void		 bufferc(struct termp *, char);
 static	void		 encode(struct termp *, const char *, size_t);
 static	void		 encode1(struct termp *, int);
+static	void		 endline(struct termp *);
 
 
 void
@@ -169,10 +170,10 @@ term_flushln(struct termp *p)
 		 * Find out whether we would exceed the right margin.
 		 * If so, break to the next line.
 		 */
-		if (vend > bp && 0 == jhy && vis > 0) {
+		if (vend > bp && 0 == jhy && vis > 0 &&
+		    (p->flags & TERMP_BRNEVER) == 0) {
 			vend -= vis;
-			(*p->endline)(p);
-			p->viscol = 0;
+			endline(p);
 
 			/* Use pending tabs on the new line. */
 
@@ -243,31 +244,37 @@ term_flushln(struct termp *p)
 		vis = 0;
 
 	p->col = 0;
+	p->minbl = p->trailspace;
 	p->flags &= ~(TERMP_BACKAFTER | TERMP_BACKBEFORE | TERMP_NOPAD);
 
-	if ( ! (TERMP_NOBREAK & p->flags)) {
-		p->viscol = 0;
-		p->minbl = 0;
-		(*p->endline)(p);
-		return;
-	}
-
-	if (TERMP_HANG & p->flags) {
-		p->minbl = p->trailspace;
-		return;
-	}
-
 	/* Trailing whitespace is significant in some columns. */
 	if (vis && vbl && (TERMP_BRTRSP & p->flags))
 		vis += vbl;
 
 	/* If the column was overrun, break the line. */
-	if (maxvis < vis + p->trailspace * (*p->width)(p, ' ')) {
-		(*p->endline)(p);
-		p->viscol = 0;
-		p->minbl = 0;
-	} else
-		p->minbl = p->trailspace;
+	if ((p->flags & TERMP_NOBREAK) == 0 ||
+	    ((p->flags & TERMP_HANG) == 0 &&
+	     vis + p->trailspace * (*p->width)(p, ' ') > maxvis))
+		endline(p);
+}
+
+static void
+endline(struct termp *p)
+{
+	if ((p->flags & (TERMP_NEWMC | TERMP_ENDMC)) == TERMP_ENDMC) {
+		p->mc = NULL;
+		p->flags &= ~TERMP_ENDMC;
+	}
+	if (p->mc != NULL) {
+		if (p->viscol && p->maxrmargin >= p->viscol)
+			(*p->advance)(p, p->maxrmargin - p->viscol + 1);
+		p->flags |= TERMP_NOBUF | TERMP_NOSPACE;
+		term_word(p, p->mc);
+		p->flags &= ~(TERMP_NOBUF | TERMP_NEWMC);
+	}
+	p->viscol = 0;
+	p->minbl = 0;
+	(*p->endline)(p);
 }
 
 /*
@@ -296,6 +303,7 @@ term_vspace(struct termp *p)
 
 	term_newln(p);
 	p->viscol = 0;
+	p->minbl = 0;
 	if (0 < p->skipvsp)
 		p->skipvsp--;
 	else
@@ -370,24 +378,24 @@ term_word(struct termp *p, const char *word)
 	size_t		 csz, lsz, ssz;
 	enum mandoc_esc	 esc;
 
-	if ( ! (TERMP_NOSPACE & p->flags)) {
-		if ( ! (TERMP_KEEP & p->flags)) {
-			bufferc(p, ' ');
-			if (TERMP_SENTENCE & p->flags)
+	if ((p->flags & TERMP_NOBUF) == 0) {
+		if ((p->flags & TERMP_NOSPACE) == 0) {
+			if ((p->flags & TERMP_KEEP) == 0) {
 				bufferc(p, ' ');
-		} else
-			bufferc(p, ASCII_NBRSP);
+				if (p->flags & TERMP_SENTENCE)
+					bufferc(p, ' ');
+			} else
+				bufferc(p, ASCII_NBRSP);
+		}
+		if (p->flags & TERMP_PREKEEP)
+			p->flags |= TERMP_KEEP;
+		if (p->flags & TERMP_NONOSPACE)
+			p->flags |= TERMP_NOSPACE;
+		else
+			p->flags &= ~TERMP_NOSPACE;
+		p->flags &= ~(TERMP_SENTENCE | TERMP_NONEWLINE);
+		p->skipvsp = 0;
 	}
-	if (TERMP_PREKEEP & p->flags)
-		p->flags |= TERMP_KEEP;
-
-	if ( ! (p->flags & TERMP_NONOSPACE))
-		p->flags &= ~TERMP_NOSPACE;
-	else
-		p->flags |= TERMP_NOSPACE;
-
-	p->flags &= ~(TERMP_SENTENCE | TERMP_NONEWLINE);
-	p->skipvsp = 0;
 
 	while ('\0' != *word) {
 		if ('\\' != *word) {
@@ -590,10 +598,12 @@ adjbuf(struct termp *p, size_t sz)
 static void
 bufferc(struct termp *p, char c)
 {
-
+	if (p->flags & TERMP_NOBUF) {
+		(*p->letter)(p, c);
+		return;
+	}
 	if (p->col + 1 >= p->maxcols)
 		adjbuf(p, p->col + 1);
-
 	p->buf[p->col++] = c;
 }
 
@@ -607,6 +617,11 @@ encode1(struct termp *p, int c)
 {
 	enum termfont	  f;
 
+	if (p->flags & TERMP_NOBUF) {
+		(*p->letter)(p, c);
+		return;
+	}
+
 	if (p->col + 7 >= p->maxcols)
 		adjbuf(p, p->col + 7);
 
@@ -643,6 +658,12 @@ encode(struct termp *p, const char *word, size_t sz)
 {
 	size_t		  i;
 
+	if (p->flags & TERMP_NOBUF) {
+		for (i = 0; i < sz; i++)
+			(*p->letter)(p, word[i]);
+		return;
+	}
+
 	if (p->col + 2 + (sz * 5) >= p->maxcols)
 		adjbuf(p, p->col + 2 + (sz * 5));
 
diff --git a/term.h b/term.h
index 58def3a1..a4dbdf42 100644
--- a/term.h
+++ b/term.h
@@ -36,8 +36,6 @@ enum	termfont {
 	TERMFONT__MAX
 };
 
-#define	TERM_MAXMARGIN	  100000 /* FIXME */
-
 struct	eqn;
 struct	roff_meta;
 struct	roff_node;
@@ -87,6 +85,10 @@ struct	termp {
 #define	TERMP_NOSPLIT	 (1 << 13)	/* Do not break line before .An. */
 #define	TERMP_SPLIT	 (1 << 14)	/* Break line before .An. */
 #define	TERMP_NONEWLINE	 (1 << 15)	/* No line break in nofill mode. */
+#define	TERMP_BRNEVER	 (1 << 16)	/* Don't even break at maxrmargin. */
+#define	TERMP_NOBUF	 (1 << 17)	/* Bypass output buffer. */
+#define	TERMP_NEWMC	 (1 << 18)	/* No .mc printed yet. */
+#define	TERMP_ENDMC	 (1 << 19)	/* Next break ends .mc mode. */
 	int		 *buf;		/* Output buffer. */
 	enum termenc	  enc;		/* Type of encoding. */
 	enum termfont	  fontl;	/* Last font set. */
@@ -105,6 +107,7 @@ struct	termp {
 	int		(*hspan)(const struct termp *,
 				const struct roffsu *);
 	const void	 *argf;		/* arg for headf/footf */
+	const char	 *mc;		/* Margin character. */
 	struct termp_ps	 *ps;
 };