Multiple parser and formatter fixes for line drawing in tbl(7).

* Allow mixing vertical line bars with the layout options
of the preceding layout cell.
* Correctly combine box options with layout lines.
* Correctly print vertical lines in data rows, with the right spacing.
* Correctly print cross markers and left and right ends of
horizontal lines even if vertical lines differ above and below.
* Avoid the bogus error message "no table data cells"
when a table data section starts with a horizontal line.
No increase in code size.

5 files changed, 160 insertions, 158 deletions

diff --git a/mandoc.h b/mandoc.h
index 3148221b..47cd7292 100644
--- a/mandoc.h
+++ b/mandoc.h
@@ -206,6 +206,8 @@ struct	tbl_opts {
 #define	TBL_OPT_NOSPACE	 (1 << 6)
 #define	TBL_OPT_NOWARN	 (1 << 7)
 	int		  cols; /* number of columns */
+	int		  lvert; /* width of left vertical line */
+	int		  rvert; /* width of right vertical line */
 };
 
 /*
@@ -215,7 +217,6 @@ struct	tbl_opts {
  */
 struct	tbl_head {
 	int		  ident; /* 0 <= unique id < cols */
-	int		  vert; /* width of preceding vertical line */
 	struct tbl_head	 *next;
 	struct tbl_head	 *prev;
 };
@@ -238,7 +239,7 @@ enum	tbl_cellt {
  */
 struct	tbl_cell {
 	struct tbl_cell	 *next;
-	int		  vert; /* width of preceding vertical line */
+	int		  vert; /* width of subsequent vertical line */
 	enum tbl_cellt	  pos;
 	size_t		  spacing;
 	int		  flags;
@@ -260,7 +261,7 @@ struct	tbl_row {
 	struct tbl_row	 *next;
 	struct tbl_cell	 *first;
 	struct tbl_cell	 *last;
-	int		  vert; /* trailing vertical line */
+	int		  vert; /* width of left vertical line */
 };
 
 enum	tbl_datt {
@@ -299,12 +300,13 @@ struct	tbl_span {
 	struct tbl_row	 *layout; /* layout row */
 	struct tbl_dat	 *first;
 	struct tbl_dat	 *last;
+	struct tbl_span	 *prev;
+	struct tbl_span	 *next;
 	int		  line; /* parse line */
 	int		  flags;
 #define	TBL_SPAN_FIRST	 (1 << 0)
 #define	TBL_SPAN_LAST	 (1 << 1)
 	enum tbl_spant	  pos;
-	struct tbl_span	 *next;
 };
 
 enum	eqn_boxt {
diff --git a/tbl.c b/tbl.c
index 20ccb389..7019f4d2 100644
--- a/tbl.c
+++ b/tbl.c
@@ -173,11 +173,15 @@ void
 tbl_end(struct tbl_node **tblp)
 {
 	struct tbl_node	*tbl;
+	struct tbl_span *sp;
 
 	tbl = *tblp;
 	*tblp = NULL;
 
-	if (NULL == tbl->first_span || NULL == tbl->first_span->first)
+	sp = tbl->first_span;
+	while (sp != NULL && sp->first == NULL)
+		sp = sp->next;
+	if (sp == NULL)
 		mandoc_msg(MANDOCERR_TBLNODATA, tbl->parse,
 		    tbl->line, tbl->pos, NULL);
 
diff --git a/tbl_data.c b/tbl_data.c
index 33a91e86..2b889542 100644
--- a/tbl_data.c
+++ b/tbl_data.c
@@ -1,7 +1,7 @@
 /*	$Id$ */
 /*
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2011 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
@@ -190,15 +190,15 @@ newspan(struct tbl_node *tbl, int line, struct tbl_row *rp)
 	dp->opts = &tbl->opts;
 	dp->layout = rp;
 	dp->head = tbl->first_head;
+	dp->prev = tbl->last_span;
 
-	if (tbl->last_span) {
-		tbl->last_span->next = dp;
-		tbl->last_span = dp;
-	} else {
-		tbl->last_span = tbl->first_span = dp;
+	if (dp->prev == NULL) {
+		tbl->first_span = dp;
 		tbl->current_span = NULL;
 		dp->flags |= TBL_SPAN_FIRST;
-	}
+	} else
+		dp->prev->next = dp;
+	tbl->last_span = dp;
 
 	return(dp);
 }
diff --git a/tbl_layout.c b/tbl_layout.c
index 7ca81659..adf728aa 100644
--- a/tbl_layout.c
+++ b/tbl_layout.c
@@ -54,7 +54,7 @@ static	void		 mods(struct tbl_node *, struct tbl_cell *,
 static	void		 cell(struct tbl_node *, struct tbl_row *,
 				int, const char *, int *);
 static	struct tbl_cell *cell_alloc(struct tbl_node *, struct tbl_row *,
-				enum tbl_cellt, int vert);
+				enum tbl_cellt);
 
 
 static void
@@ -69,7 +69,7 @@ mod:
 
 	/* Row delimiters and cell specifiers end modifier lists. */
 
-	if (strchr(".,-=^_ACLNRSaclnrs|", p[*pos]) != NULL)
+	if (strchr(".,-=^_ACLNRSaclnrs", p[*pos]) != NULL)
 		return;
 
 	/* Throw away parenthesised expression. */
@@ -137,6 +137,13 @@ mod:
 	case 'z':
 		cp->flags |= TBL_CELL_WIGN;
 		goto mod;
+	case '|':
+		if (cp->vert < 2)
+			cp->vert++;
+		else
+			mandoc_msg(MANDOCERR_TBLLAYOUT_VERT,
+			    tbl->parse, ln, *pos - 1, NULL);
+		goto mod;
 	default:
 		mandoc_vmsg(MANDOCERR_TBLLAYOUT_CHAR, tbl->parse,
 		    ln, *pos - 1, "%c", p[*pos - 1]);
@@ -169,17 +176,15 @@ static void
 cell(struct tbl_node *tbl, struct tbl_row *rp,
 		int ln, const char *p, int *pos)
 {
-	int		 vert, i;
+	int		 i;
 	enum tbl_cellt	 c;
 
-	/* Handle vertical lines. */
+	/* Handle leading vertical lines */
 
-	vert = 0;
-again:
 	while (p[*pos] == ' ' || p[*pos] == '\t' || p[*pos] == '|') {
 		if (p[*pos] == '|') {
-			if (vert < 2)
-				vert++;
+			if (rp->vert < 2)
+				rp->vert++;
 			else
 				mandoc_msg(MANDOCERR_TBLLAYOUT_VERT,
 				    tbl->parse, ln, *pos, NULL);
@@ -187,12 +192,12 @@ again:
 		(*pos)++;
 	}
 
-	/* Handle trailing vertical lines */
+again:
+	while (p[*pos] == ' ' || p[*pos] == '\t')
+		(*pos)++;
 
-	if ('.' == p[*pos] || '\0' == p[*pos]) {
-		rp->vert = vert;
+	if (p[*pos] == '.' || p[*pos] == '\0')
 		return;
-	}
 
 	/* Parse the column position (`c', `l', `r', ...). */
 
@@ -225,7 +230,7 @@ again:
 
 	/* Allocate cell then parse its modifiers. */
 
-	mods(tbl, cell_alloc(tbl, rp, c, vert), ln, p, pos);
+	mods(tbl, cell_alloc(tbl, rp, c), ln, p, pos);
 }
 
 void
@@ -253,13 +258,34 @@ tbl_layout(struct tbl_node *tbl, int ln, const char *p)
 		case '.':  /* End of layout. */
 			pos++;
 			tbl->part = TBL_PART_DATA;
-			if (tbl->first_row != NULL)
+
+			/*
+			 * When the layout is completely empty,
+			 * default to one left-justified column.
+			 */
+
+			if (tbl->first_row == NULL) {
+				mandoc_msg(MANDOCERR_TBLLAYOUT_NONE,
+				    tbl->parse, ln, pos, NULL);
+				rp = mandoc_calloc(1, sizeof(*rp));
+				cell_alloc(tbl, rp, TBL_CELL_LEFT);
+				tbl->first_row = tbl->last_row = rp;
 				return;
-			mandoc_msg(MANDOCERR_TBLLAYOUT_NONE,
-			    tbl->parse, ln, pos, NULL);
-			rp = mandoc_calloc(1, sizeof(*rp));
-			cell_alloc(tbl, rp, TBL_CELL_LEFT, 0);
-			tbl->first_row = tbl->last_row = rp;
+			}
+
+			/*
+			 * Search for the widest line
+			 * along the left and right margins.
+			 */
+
+			for (rp = tbl->first_row; rp; rp = rp->next) {
+				if (tbl->opts.lvert < rp->vert)
+					tbl->opts.lvert = rp->vert;
+				if (rp->last != NULL &&
+				    rp->last->head == tbl->last_head &&
+				    tbl->opts.rvert < rp->last->vert)
+					tbl->opts.rvert = rp->last->vert;
+			}
 			return;
 		default:  /* Cell. */
 			break;
@@ -278,8 +304,7 @@ tbl_layout(struct tbl_node *tbl, int ln, const char *p)
 }
 
 static struct tbl_cell *
-cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos,
-		int vert)
+cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos)
 {
 	struct tbl_cell	*p, *pp;
 	struct tbl_head	*h, *hp;
@@ -296,7 +321,6 @@ cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos,
 	rp->last = p;
 
 	p->pos = pos;
-	p->vert = vert;
 
 	/* Re-use header. */
 
@@ -307,7 +331,6 @@ cell_alloc(struct tbl_node *tbl, struct tbl_row *rp, enum tbl_cellt pos,
 
 	hp = mandoc_calloc(1, sizeof(struct tbl_head));
 	hp->ident = tbl->opts.cols++;
-	hp->vert = vert;
 
 	if (tbl->last_head) {
 		hp->prev = tbl->last_head;
diff --git a/tbl_term.c b/tbl_term.c
index 25c32cdb..d53f1797 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 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2011, 2012, 2014, 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
@@ -34,15 +34,12 @@ static	void	tbl_char(struct termp *, char, size_t);
 static	void	tbl_data(struct termp *, const struct tbl_opts *,
 			const struct tbl_dat *,
 			const struct roffcol *);
-static	size_t	tbl_rulewidth(struct termp *, const struct tbl_head *);
-static	void	tbl_hframe(struct termp *, const struct tbl_span *, int);
 static	void	tbl_literal(struct termp *, const struct tbl_dat *,
 			const struct roffcol *);
 static	void	tbl_number(struct termp *, const struct tbl_opts *,
 			const struct tbl_dat *,
 			const struct roffcol *);
-static	void	tbl_hrule(struct termp *, const struct tbl_span *);
-static	void	tbl_vrule(struct termp *, const struct tbl_head *);
+static	void	tbl_hrule(struct termp *, const struct tbl_span *, int);
 static	void	tbl_word(struct termp *, const struct tbl_dat *);
 
 
@@ -64,9 +61,9 @@ void
 term_tbl(struct termp *tp, const struct tbl_span *sp)
 {
 	const struct tbl_head	*hp;
+	const struct tbl_cell	*cp;
 	const struct tbl_dat	*dp;
-	struct roffcol		*col;
-	int			 spans;
+	int			 horiz, spans, vert;
 	size_t			 rmargin, maxrmargin;
 
 	rmargin = tp->rmargin;
@@ -84,7 +81,7 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 	 * calculate the table widths and decimal positions.
 	 */
 
-	if (TBL_SPAN_FIRST & sp->flags) {
+	if (sp->flags & TBL_SPAN_FIRST) {
 		term_flushln(tp);
 
 		tp->tbl.len = term_tbl_len;
@@ -92,24 +89,25 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 		tp->tbl.arg = tp;
 
 		tblcalc(&tp->tbl, sp, rmargin - tp->offset);
-	}
 
-	/* Horizontal frame at the start of boxed tables. */
+		/* Horizontal frame at the start of boxed tables. */
 
-	if (TBL_SPAN_FIRST & sp->flags) {
-		if (TBL_OPT_DBOX & sp->opts->opts)
-			tbl_hframe(tp, sp, 1);
-		if (TBL_OPT_DBOX & sp->opts->opts ||
-		    TBL_OPT_BOX  & sp->opts->opts)
-			tbl_hframe(tp, sp, 0);
+		if (sp->opts->opts & TBL_OPT_DBOX)
+			tbl_hrule(tp, sp, 2);
+		if (sp->opts->opts & (TBL_OPT_DBOX | TBL_OPT_BOX))
+			tbl_hrule(tp, sp, 1);
 	}
 
 	/* Vertical frame at the start of each row. */
 
-	if ((TBL_OPT_BOX | TBL_OPT_DBOX) & sp->opts->opts ||
-	    (sp->head != NULL && sp->head->vert))
-		term_word(tp, TBL_SPAN_HORIZ == sp->pos ||
-		    TBL_SPAN_DHORIZ == sp->pos ? "+" : "|");
+	horiz = sp->pos == TBL_SPAN_HORIZ || sp->pos == TBL_SPAN_DHORIZ;
+
+	if (sp->layout->vert ||
+	    (sp->prev != NULL && sp->prev->layout->vert) ||
+	    sp->opts->opts & (TBL_OPT_BOX | TBL_OPT_DBOX))
+		term_word(tp, horiz ? "+" : "|");
+	else if (sp->opts->lvert)
+		tbl_char(tp, horiz ? '-' : ASCII_NBRSP, 1);
 
 	/*
 	 * Now print the actual data itself depending on the span type.
@@ -117,54 +115,61 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 	 * data printed by matching data to header.
 	 */
 
-	switch (sp->pos) {
-	case TBL_SPAN_HORIZ:
-		/* FALLTHROUGH */
-	case TBL_SPAN_DHORIZ:
-		tbl_hrule(tp, sp);
-		break;
-	case TBL_SPAN_DATA:
+	if (sp->pos == TBL_SPAN_DATA) {
 		/* Iterate over template headers. */
+		cp = sp->layout->first;
 		dp = sp->first;
 		spans = 0;
-		for (hp = sp->head; hp; hp = hp->next) {
+		for (hp = sp->head; hp != NULL; hp = hp->next) {
 
 			/*
-			 * If the current data header is invoked during
-			 * a spanner ("spans" > 0), don't emit anything
-			 * at all.
+			 * Remeber whether we need a vertical bar
+			 * after this cell.
 			 */
 
-			if (--spans >= 0)
-				continue;
-
-			/* Separate columns. */
+			vert = cp == NULL ? 0 : cp->vert;
 
-			if (NULL != hp->prev)
-				tbl_vrule(tp, hp);
+			/*
+			 * Print the data and advance to the next cell.
+			 */
 
-			col = &tp->tbl.cols[hp->ident];
-			tbl_data(tp, sp->opts, dp, col);
+			if (spans == 0) {
+				tbl_data(tp, sp->opts, dp,
+				    tp->tbl.cols + hp->ident);
+				if (dp != NULL) {
+					spans = dp->spans;
+					dp = dp->next;
+				}
+			} else
+				spans--;
+			if (cp != NULL)
+				cp = cp->next;
 
 			/*
-			 * Go to the next data cell and assign the
-			 * number of subsequent spans, if applicable.
+			 * Separate columns, except in the middle
+			 * of spans and after the last cell.
 			 */
 
-			if (dp) {
-				spans = dp->spans;
-				dp = dp->next;
-			}
+			if (hp->next == NULL || spans)
+				continue;
+
+			tbl_char(tp, ASCII_NBRSP, 1);
+			if (vert > 0)
+				tbl_char(tp, '|', vert);
+			if (vert < 2 && hp->next != NULL)
+				tbl_char(tp, ASCII_NBRSP, 2 - vert);
 		}
-		break;
-	}
+	} else if (horiz)
+		tbl_hrule(tp, sp, 0);
 
 	/* Vertical frame at the end of each row. */
 
-	if ((TBL_OPT_BOX | TBL_OPT_DBOX) & sp->opts->opts ||
-	    sp->layout->vert)
-		term_word(tp, TBL_SPAN_HORIZ == sp->pos ||
-		    TBL_SPAN_DHORIZ == sp->pos ? "+" : " |");
+	if (sp->layout->last->vert ||
+	    (sp->prev != NULL && sp->prev->layout->last->vert) ||
+	    (sp->opts->opts & (TBL_OPT_BOX | TBL_OPT_DBOX)))
+		term_word(tp, horiz ? "+" : " |");
+	else if (sp->opts->rvert)
+		tbl_char(tp, horiz ? '-' : ASCII_NBRSP, 1);
 	term_flushln(tp);
 
 	/*
@@ -172,14 +177,13 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 	 * existing table configuration and set it to NULL.
 	 */
 
-	if (TBL_SPAN_LAST & sp->flags) {
-		if (TBL_OPT_DBOX & sp->opts->opts ||
-		    TBL_OPT_BOX  & sp->opts->opts) {
-			tbl_hframe(tp, sp, 0);
+	if (sp->flags & TBL_SPAN_LAST) {
+		if (sp->opts->opts & (TBL_OPT_DBOX | TBL_OPT_BOX)) {
+			tbl_hrule(tp, sp, 1);
 			tp->skipvsp = 1;
 		}
-		if (TBL_OPT_DBOX & sp->opts->opts) {
-			tbl_hframe(tp, sp, 1);
+		if (sp->opts->opts & TBL_OPT_DBOX) {
+			tbl_hrule(tp, sp, 2);
 			tp->skipvsp = 2;
 		}
 		assert(tp->tbl.cols);
@@ -194,66 +198,46 @@ term_tbl(struct termp *tp, const struct tbl_span *sp)
 }
 
 /*
- * Horizontal rules extend across the entire table.
- * Calculate the width by iterating over columns.
- */
-static size_t
-tbl_rulewidth(struct termp *tp, const struct tbl_head *hp)
-{
-	size_t		 width;
-
-	width = tp->tbl.cols[hp->ident].width;
-
-	/* Account for leading blanks. */
-	if (hp->prev)
-		width += 2 - hp->vert;
-
-	/* Account for trailing blank. */
-	width++;
-
-	return(width);
-}
-
-/*
- * Rules inside the table can be single or double
- * and have crossings with vertical rules marked with pluses.
+ * Kinds of horizontal rulers:
+ * 0: inside the table (single or double line with crossings)
+ * 1: inner frame (single line with crossings and ends)
+ * 2: outer frame (single line without crossings with ends)
  */
 static void
-tbl_hrule(struct termp *tp, const struct tbl_span *sp)
+tbl_hrule(struct termp *tp, const struct tbl_span *sp, int kind)
 {
-	const struct tbl_head *hp;
-	char		 c;
-
-	c = '-';
-	if (TBL_SPAN_DHORIZ == sp->pos)
-		c = '=';
-
-	for (hp = sp->head; hp; hp = hp->next) {
-		if (hp->prev && hp->vert)
-			tbl_char(tp, '+', hp->vert);
-		tbl_char(tp, c, tbl_rulewidth(tp, hp));
+	const struct tbl_cell *c1, *c2;
+	int	 vert;
+	char	 line, cross;
+
+	line = (kind == 0 && TBL_SPAN_DHORIZ == sp->pos) ? '=' : '-';
+	cross = (kind < 2) ? '+' : '-';
+
+	if (kind)
+		term_word(tp, "+");
+	c1 = sp->layout->first;
+	c2 = sp->prev == NULL ? NULL : sp->prev->layout->first;
+	if (c2 == c1)
+		c2 = NULL;
+	for (;;) {
+		tbl_char(tp, line, tp->tbl.cols[c1->head->ident].width + 1);
+		vert = c1->vert;
+		if ((c1 = c1->next) == NULL)
+			 break;
+		if (c2 != NULL) {
+			if (vert < c2->vert)
+				vert = c2->vert;
+			c2 = c2->next;
+		}
+		if (vert)
+			tbl_char(tp, cross, vert);
+		if (vert < 2)
+			tbl_char(tp, line, 2 - vert);
 	}
-}
-
-/*
- * Rules above and below the table are always single
- * and have an additional plus at the beginning and end.
- * For double frames, this function is called twice,
- * and the outer one does not have crossings.
- */
-static void
-tbl_hframe(struct termp *tp, const struct tbl_span *sp, int outer)
-{
-	const struct tbl_head *hp;
-
-	term_word(tp, "+");
-	for (hp = sp->head; hp; hp = hp->next) {
-		if (hp->prev && hp->vert)
-			tbl_char(tp, (outer ? '-' : '+'), hp->vert);
-		tbl_char(tp, '-', tbl_rulewidth(tp, hp));
+	if (kind) {
+		term_word(tp, "+");
+		term_flushln(tp);
 	}
-	term_word(tp, "+");
-	term_flushln(tp);
 }
 
 static void
@@ -315,17 +299,6 @@ tbl_data(struct termp *tp, const struct tbl_opts *opts,
 }
 
 static void
-tbl_vrule(struct termp *tp, const struct tbl_head *hp)
-{
-
-	tbl_char(tp, ASCII_NBRSP, 1);
-	if (0 < hp->vert)
-		tbl_char(tp, '|', hp->vert);
-	if (2 > hp->vert)
-		tbl_char(tp, ASCII_NBRSP, 2 - hp->vert);
-}
-
-static void
 tbl_char(struct termp *tp, char c, size_t len)
 {
 	size_t		i, sz;