Bringing spacing more in line with groff, patches from schwarze@openbsd.org. Pre-testing.

3 files changed, 50 insertions, 45 deletions

diff --git a/mdoc_term.c b/mdoc_term.c
index bdd63db5..148aaaf5 100644
--- a/mdoc_term.c
+++ b/mdoc_term.c
@@ -1,4 +1,4 @@
-/*	$Id: mdoc_term.c,v 1.50 2009/07/21 12:47:52 kristaps Exp $ */
+/*	$Id: mdoc_term.c,v 1.51 2009/07/21 13:34:13 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -812,18 +812,22 @@ termp_it_pre(DECL_ARGS)
 	 * while diagonal bodies need two.
 	 */
 
+	p->flags |= TERMP_NOSPACE;
+
 	switch (type) {
+	case (MDOC_Diag):
+		term_word(p, "\\ \\ ");
+		break;
 	case (MDOC_Inset):
 		if (MDOC_BODY == node->type) 
-			p->flags &= ~TERMP_NOSPACE;
-		else
-			p->flags |= TERMP_NOSPACE;
+			term_word(p, "\\ ");
 		break;
 	default:
-		p->flags |= TERMP_NOSPACE;
 		break;
 	}
 
+	p->flags |= TERMP_NOSPACE;
+
 	/*
 	 * Style flags.  Diagnostic heads need TTYPE_DIAG.
 	 */
@@ -869,7 +873,7 @@ termp_it_pre(DECL_ARGS)
 		break;
 	case (MDOC_Tag):
 		if (MDOC_HEAD == node->type)
-			p->flags |= TERMP_NOBREAK;
+			p->flags |= TERMP_NOBREAK | TERMP_TWOSPACE;
 		else
 			p->flags |= TERMP_NOLPAD;
 
@@ -1009,9 +1013,6 @@ termp_it_post(DECL_ARGS)
 	assert(-1 != type);
 
 	switch (type) {
-	case (MDOC_Diag):
-		term_word(p, "\\ ");
-		/* FALLTHROUGH */
 	case (MDOC_Item):
 		/* FALLTHROUGH */
 	case (MDOC_Inset):
diff --git a/term.c b/term.c
index 4d33ce8d..f7b92697 100644
--- a/term.c
+++ b/term.c
@@ -1,4 +1,4 @@
-/*	$Id: term.c,v 1.90 2009/07/19 21:26:27 kristaps Exp $ */
+/*	$Id: term.c,v 1.91 2009/07/21 13:34:13 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -184,6 +184,9 @@ term_isopendelim(const char *p)
  *    columns.  In short: don't print a newline and instead pad to the
  *    right margin.  Used in conjunction with TERMP_NOLPAD.
  *
+ *  - TERMP_TWOSPACE: when padding, make sure there are at least two
+ *    space characters of padding.  Otherwise, rather break the line.
+ *
  *  - TERMP_DANGLE: don't newline when TERMP_NOBREAK is specified and
  *    the line is overrun, and don't pad-right if it's underrun.
  *
@@ -214,7 +217,7 @@ term_flushln(struct termp *p)
 {
 	int		 i, j;
 	size_t		 vbl, vsz, vis, maxvis, mmax, bp;
-	static int	 sv = -1;
+	static int	 overstep = 0;
 
 	/*
 	 * First, establish the maximum columns of "visible" content.
@@ -224,15 +227,11 @@ term_flushln(struct termp *p)
 	 */
 
 	assert(p->offset < p->rmargin);
-	maxvis = p->rmargin - p->offset;
-	mmax = p->maxrmargin - p->offset;
+	maxvis = p->rmargin - p->offset - overstep;
+	mmax = p->maxrmargin - p->offset - overstep;
 	bp = TERMP_NOBREAK & p->flags ? mmax : maxvis;
 	vis = 0;
-
-	if (sv >= 0) {
-		vis = (size_t)sv;
-		sv = -1;
-	}
+	overstep = 0;
 
 	/*
 	 * If in the standard case (left-justified), then begin with our
@@ -302,38 +301,42 @@ term_flushln(struct termp *p)
 		}
 		vis += vsz;
 	}
+	p->col = 0;
 
-	/*
-	 * If we've overstepped our maximum visible no-break space, then
-	 * cause a newline and offset at the right margin.
-	 */
-
-	if ((TERMP_NOBREAK & p->flags) && vis >= maxvis) {
-		if ( ! (TERMP_DANGLE & p->flags) &&
-				! (TERMP_HANG & p->flags)) {
-			putchar('\n');
-			for (i = 0; i < (int)p->rmargin; i++)
-				putchar(' ');
-		}
-		if (TERMP_HANG & p->flags)
-			sv = (int)(vis - maxvis);
-		p->col = 0;
+	if ( ! (TERMP_NOBREAK & p->flags)) {
+		putchar('\n');
 		return;
 	}
 
-	/*
-	 * If we're not to right-marginalise it (newline), then instead
-	 * pad to the right margin and stay off.
-	 */
+	if (TERMP_HANG & p->flags) {
 
-	if (p->flags & TERMP_NOBREAK) {
-		if ( ! (TERMP_DANGLE & p->flags))
-			for ( ; vis < maxvis; vis++)
-				putchar(' ');
-	} else
-		putchar('\n');
+		/* We need one blank after the tag. */
+		overstep = vis - maxvis + 1;
 
-	p->col = 0;
+		/*
+		 * Behave exactly the same way as groff:
+		 * If we have overstepped the margin, temporarily move it
+		 * to the right and flag the rest of the line to be shorter.
+		 * If we landed right at the margin, be happy.
+		 * If we are one step before the margin, temporarily move it
+		 * one step LEFT and flag the rest of the line to be longer.
+		 */
+		if (overstep >= -1)
+			maxvis += overstep;
+		else
+			overstep = 0;
+
+	} else if (TERMP_DANGLE & p->flags)
+		return;
+
+	if (maxvis > vis + ((TERMP_TWOSPACE & p->flags) ? 1 : 0))  /* pad */
+		for ( ; vis < maxvis; vis++)
+			putchar(' ');
+	else {	/* break */
+		putchar('\n');
+		for (i = 0; i < (int)p->rmargin; i++)
+			putchar(' ');
+	}
 }
 
 
diff --git a/term.h b/term.h
index e713cb65..ecc6317d 100644
--- a/term.h
+++ b/term.h
@@ -1,4 +1,4 @@
-/*	$Id: term.h,v 1.39 2009/07/19 09:10:42 kristaps Exp $ */
+/*	$Id: term.h,v 1.40 2009/07/21 13:34:13 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009 Kristaps Dzonsons <kristaps@kth.se>
  *
@@ -47,6 +47,7 @@ struct	termp {
 #define	TERMP_NONOSPACE	 (1 << 7)	/* No space (no autounset). */
 #define	TERMP_DANGLE	 (1 << 8)	/* See term_flushln(). */
 #define	TERMP_HANG	 (1 << 9)	/* See term_flushln(). */
+#define	TERMP_TWOSPACE	 (1 << 9)	/* See term_flushln(). */
 	char		 *buf;		/* Output buffer. */
 	enum termenc	  enc;		/* Type of encoding. */
 	void		 *symtab;	/* Encoded-symbol table. */