===================================================================
RCS file: /cvs/mandoc/out.c,v
retrieving revision 1.74
retrieving revision 1.75
diff -u -p -r1.74 -r1.75
--- mandoc/out.c	2018/11/25 19:24:20	1.74
+++ mandoc/out.c	2018/11/29 01:55:02	1.75
@@ -1,4 +1,4 @@
-/*	$Id: out.c,v 1.74 2018/11/25 19:24:20 schwarze Exp $ */
+/*	$Id: out.c,v 1.75 2018/11/29 01:55:02 schwarze Exp $ */
 /*
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011,2014,2015,2017,2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -30,12 +30,19 @@
 #include "mandoc.h"
 #include "out.h"
 
-static	void	tblcalc_data(struct rofftbl *, struct roffcol *,
+struct	tbl_colgroup {
+	struct tbl_colgroup	*next;
+	size_t			 wanted;
+	int			 startcol;
+	int			 endcol;
+};
+
+static	size_t	tblcalc_data(struct rofftbl *, struct roffcol *,
 			const struct tbl_opts *, const struct tbl_dat *,
 			size_t);
-static	void	tblcalc_literal(struct rofftbl *, struct roffcol *,
+static	size_t	tblcalc_literal(struct rofftbl *, struct roffcol *,
 			const struct tbl_dat *, size_t);
-static	void	tblcalc_number(struct rofftbl *, struct roffcol *,
+static	size_t	tblcalc_number(struct rofftbl *, struct roffcol *,
 			const struct tbl_opts *, const struct tbl_dat *);
 
 
@@ -104,16 +111,18 @@ a2roffsu(const char *src, struct roffsu *dst, enum rof
  * used for the actual width calculations.
  */
 void
-tblcalc(struct rofftbl *tbl, const struct tbl_span *sp,
+tblcalc(struct rofftbl *tbl, const struct tbl_span *sp_first,
     size_t offset, size_t rmargin)
 {
 	struct roffsu		 su;
 	const struct tbl_opts	*opts;
+	const struct tbl_span	*sp;
 	const struct tbl_dat	*dp;
 	struct roffcol		*col;
-	size_t			 ewidth, xwidth;
-	int			 hspans;
-	int			 icol, maxcol, necol, nxcol, quirkcol;
+	struct tbl_colgroup	*first_group, **gp, *g;
+	size_t			*colwidth;
+	size_t			 ewidth, min1, min2, wanted, width, xwidth;
+	int			 done, icol, maxcol, necol, nxcol, quirkcol;
 
 	/*
 	 * Allocate the master column specifiers.  These will hold the
@@ -121,33 +130,34 @@ tblcalc(struct rofftbl *tbl, const struct tbl_span *sp
 	 * must be freed and nullified by the caller.
 	 */
 
-	assert(NULL == tbl->cols);
-	tbl->cols = mandoc_calloc((size_t)sp->opts->cols,
+	assert(tbl->cols == NULL);
+	tbl->cols = mandoc_calloc((size_t)sp_first->opts->cols,
 	    sizeof(struct roffcol));
-	opts = sp->opts;
+	opts = sp_first->opts;
 
-	for (maxcol = -1; sp; sp = sp->next) {
-		if (TBL_SPAN_DATA != sp->pos)
+	maxcol = -1;
+	first_group = NULL;
+	for (sp = sp_first; sp != NULL; sp = sp->next) {
+		if (sp->pos != TBL_SPAN_DATA)
 			continue;
-		hspans = 1;
+
 		/*
 		 * Account for the data cells in the layout, matching it
 		 * to data cells in the data section.
 		 */
-		for (dp = sp->first; dp; dp = dp->next) {
-			/* Do not used spanned cells in the calculation. */
-			if (0 < --hspans)
-				continue;
-			hspans = dp->hspans;
-			if (1 < hspans)
-				continue;
+
+		gp = &first_group;
+		for (dp = sp->first; dp != NULL; dp = dp->next) {
 			icol = dp->layout->col;
-			while (maxcol < icol)
+			while (icol > maxcol)
 				tbl->cols[++maxcol].spacing = SIZE_MAX;
 			col = tbl->cols + icol;
 			col->flags |= dp->layout->flags;
 			if (dp->layout->flags & TBL_CELL_WIGN)
 				continue;
+
+			/* Handle explicit width specifications. */
+
 			if (dp->layout->wstr != NULL &&
 			    dp->layout->width == 0 &&
 			    a2roffsu(dp->layout->wstr, &su, SCALE_EN)
@@ -160,15 +170,164 @@ tblcalc(struct rofftbl *tbl, const struct tbl_span *sp
 			    (col->spacing == SIZE_MAX ||
 			     col->spacing < dp->layout->spacing))
 				col->spacing = dp->layout->spacing;
-			tblcalc_data(tbl, col, opts, dp,
+
+			/*
+			 * Calculate an automatic width.
+			 * Except for spanning cells, apply it.
+			 */
+
+			width = tblcalc_data(tbl,
+			    dp->hspans == 0 ? col : NULL,
+			    opts, dp,
 			    dp->block == 0 ? 0 :
 			    dp->layout->width ? dp->layout->width :
 			    rmargin ? (rmargin + sp->opts->cols / 2)
 			    / (sp->opts->cols + 1) : 0);
+			if (dp->hspans == 0)
+				continue;
+
+			/*
+			 * Build an ordered, singly linked list
+			 * of all groups of columns joined by spans,
+			 * recording the minimum width for each group.
+			 */
+
+			while (*gp != NULL && ((*gp)->startcol < icol ||
+			    (*gp)->endcol < icol + dp->hspans))
+				gp = &(*gp)->next;
+			if (*gp == NULL || (*gp)->startcol > icol ||
+                            (*gp)->endcol > icol + dp->hspans) {
+				g = mandoc_malloc(sizeof(*g));
+				g->next = *gp;
+				g->wanted = width;
+				g->startcol = icol;
+				g->endcol = icol + dp->hspans;
+				*gp = g;
+			} else if ((*gp)->wanted < width)
+				(*gp)->wanted = width;
 		}
 	}
 
 	/*
+	 * Column spacings are needed for span width calculations,
+	 * so set the default values now.
+	 */
+
+	for (icol = 0; icol <= maxcol; icol++)
+		if (tbl->cols[icol].spacing == SIZE_MAX || icol == maxcol)
+			tbl->cols[icol].spacing = 3;
+
+	/*
+	 * Replace the minimum widths with the missing widths,
+	 * and dismiss groups that are already wide enough.
+	 */
+
+	gp = &first_group;
+	while ((g = *gp) != NULL) {
+		done = 0;
+		for (icol = g->startcol; icol <= g->endcol; icol++) {
+			width = tbl->cols[icol].width;
+			if (icol < g->endcol)
+				width += tbl->cols[icol].spacing;
+			if (g->wanted <= width) {
+				done = 1;
+				break;
+			} else
+				(*gp)->wanted -= width;
+		}
+		if (done) {
+			*gp = g->next;
+			free(g);
+		} else
+			gp = &(*gp)->next;
+	}
+
+	colwidth = mandoc_reallocarray(NULL, maxcol + 1, sizeof(*colwidth));
+	while (first_group != NULL) {
+
+		/*
+		 * Rebuild the array of the widths of all columns
+		 * participating in spans that require expansion.
+		 */
+
+		for (icol = 0; icol <= maxcol; icol++)
+			colwidth[icol] = SIZE_MAX;
+		for (g = first_group; g != NULL; g = g->next)
+			for (icol = g->startcol; icol <= g->endcol; icol++)
+				colwidth[icol] = tbl->cols[icol].width;
+
+		/*
+		 * Find the smallest and second smallest column width
+		 * among the columns which may need expamsion.
+		 */
+
+		min1 = min2 = SIZE_MAX;
+		for (icol = 0; icol <= maxcol; icol++) {
+			if (min1 > colwidth[icol]) {
+				min2 = min1;
+				min1 = colwidth[icol];
+			} else if (min1 < colwidth[icol] &&
+			    min2 > colwidth[icol])
+				min2 = colwidth[icol];
+		}
+
+		/*
+		 * Find the minimum wanted width
+		 * for any one of the narrowest columns,
+		 * and mark the columns wanting that width.
+		 */
+
+		wanted = min2;
+		for (g = first_group; g != NULL; g = g->next) {
+			necol = 0;
+			for (icol = g->startcol; icol <= g->endcol; icol++)
+				if (tbl->cols[icol].width == min1)
+					necol++;
+			if (necol == 0)
+				continue;
+			width = min1 + (g->wanted - 1) / necol + 1;
+			if (width > min2)
+				width = min2;
+			if (wanted > width)
+				wanted = width;
+			for (icol = g->startcol; icol <= g->endcol; icol++)
+				if (colwidth[icol] == min1 ||
+				    (colwidth[icol] < min2 &&
+				     colwidth[icol] > width))
+					colwidth[icol] = width;
+		}
+
+		/* Record the effect of the widening on the group list. */
+
+		gp = &first_group;
+		while ((g = *gp) != NULL) {
+			done = 0;
+			for (icol = g->startcol; icol <= g->endcol; icol++) {
+				if (colwidth[icol] != wanted ||
+				    tbl->cols[icol].width == wanted)
+					continue;
+				if (g->wanted <= wanted - min1) {
+					done = 1;
+					break;
+				}
+				g->wanted -= wanted - min1;
+			}
+			if (done) {
+				*gp = g->next;
+				free(g);
+			} else
+				gp = &(*gp)->next;
+		}
+
+		/* Record the effect of the widening on the columns. */
+
+		for (icol = 0; icol <= maxcol; icol++)
+			if (colwidth[icol] == wanted)
+				tbl->cols[icol].width = wanted;
+	}
+	free(colwidth);
+
+	/*
 	 * Align numbers with text.
 	 * Count columns to equalize and columns to maximize.
 	 * Find maximum width of the columns to equalize.
@@ -183,8 +342,6 @@ tblcalc(struct rofftbl *tbl, const struct tbl_span *sp
 			col->decimal += (col->width - col->nwidth) / 2;
 		else
 			col->width = col->nwidth;
-		if (col->spacing == SIZE_MAX || icol == maxcol)
-			col->spacing = 3;
 		if (col->flags & TBL_CELL_EQUAL) {
 			necol++;
 			if (ewidth < col->width)
@@ -257,7 +414,7 @@ tblcalc(struct rofftbl *tbl, const struct tbl_span *sp
 	}
 }
 
-static void
+static size_t
 tblcalc_data(struct rofftbl *tbl, struct roffcol *col,
     const struct tbl_opts *opts, const struct tbl_dat *dp, size_t mw)
 {
@@ -269,26 +426,24 @@ tblcalc_data(struct rofftbl *tbl, struct roffcol *col,
 	case TBL_CELL_HORIZ:
 	case TBL_CELL_DHORIZ:
 		sz = (*tbl->len)(1, tbl->arg);
-		if (col->width < sz)
+		if (col != NULL && col->width < sz)
 			col->width = sz;
-		break;
+		return sz;
 	case TBL_CELL_LONG:
 	case TBL_CELL_CENTRE:
 	case TBL_CELL_LEFT:
 	case TBL_CELL_RIGHT:
-		tblcalc_literal(tbl, col, dp, mw);
-		break;
+		return tblcalc_literal(tbl, col, dp, mw);
 	case TBL_CELL_NUMBER:
-		tblcalc_number(tbl, col, opts, dp);
-		break;
+		return tblcalc_number(tbl, col, opts, dp);
 	case TBL_CELL_DOWN:
-		break;
+		return 0;
 	default:
 		abort();
 	}
 }
 
-static void
+static size_t
 tblcalc_literal(struct rofftbl *tbl, struct roffcol *col,
     const struct tbl_dat *dp, size_t mw)
 {
@@ -297,11 +452,12 @@ tblcalc_literal(struct rofftbl *tbl, struct roffcol *c
 	char		*end;	/* End of the current line. */
 	size_t		 lsz;	/* Length of the current line. */
 	size_t		 wsz;	/* Length of the current word. */
+	size_t		 msz;   /* Length of the longest line. */
 
 	if (dp->string == NULL || *dp->string == '\0')
-		return;
+		return 0;
 	str = mw ? mandoc_strdup(dp->string) : dp->string;
-	lsz = 0;
+	msz = lsz = 0;
 	for (beg = str; beg != NULL && *beg != '\0'; beg = end) {
 		end = mw ? strchr(beg, ' ') : NULL;
 		if (end != NULL) {
@@ -314,14 +470,17 @@ tblcalc_literal(struct rofftbl *tbl, struct roffcol *c
 			lsz += 1 + wsz;
 		else
 			lsz = wsz;
-		if (col->width < lsz)
-			col->width = lsz;
+		if (msz < lsz)
+			msz = lsz;
 	}
 	if (mw)
 		free((void *)str);
+	if (col != NULL && col->width < msz)
+		col->width = msz;
+	return msz;
 }
 
-static void
+static size_t
 tblcalc_number(struct rofftbl *tbl, struct roffcol *col,
 		const struct tbl_opts *opts, const struct tbl_dat *dp)
 {
@@ -330,8 +489,12 @@ tblcalc_number(struct rofftbl *tbl, struct roffcol *co
 	char		 buf[2];
 
 	if (dp->string == NULL || *dp->string == '\0')
-		return;
+		return 0;
 
+	totsz = (*tbl->slen)(dp->string, tbl->arg);
+	if (col == NULL)
+		return totsz;
+
 	/*
 	 * Find the last digit and
 	 * the last decimal point that is adjacent to a digit.
@@ -353,11 +516,10 @@ tblcalc_number(struct rofftbl *tbl, struct roffcol *co
 
 	/* Not a number, treat as a literal string. */
 
-	totsz = (*tbl->slen)(dp->string, tbl->arg);
 	if (lastdigit == NULL) {
-		if (col->width < totsz)
+		if (col != NULL && col->width < totsz)
 			col->width = totsz;
-		return;
+		return totsz;
 	}
 
 	/* Measure the width of the integer part. */
@@ -387,4 +549,5 @@ tblcalc_number(struct rofftbl *tbl, struct roffcol *co
 
 	if (totsz > col->nwidth)
 		col->nwidth = totsz;
+	return totsz;
 }