Polishing the worms in my favourite can, term_flushln().

The TERMP_TWOSPACE flag i introduced in August 2009 was idiosyncratic
and served only a very narrow purpose.  Replace it by a more intuitive
and more general termp attribute "trailspace", to be used together
with TERMP_NOBREAK, to request a minimum amount of whitespace at
the end of the current column.  Adapt all code to the new interface.

No functional change intended;
code reviews to confirm that are welcome *eg*.

1 files changed, 31 insertions, 18 deletions

diff --git a/usr.bin/mandoc/mdoc_term.c b/usr.bin/mandoc/mdoc_term.c
index 39d7314994f..aa1a687af1d 100644
--- a/usr.bin/mandoc/mdoc_term.c
+++ b/usr.bin/mandoc/mdoc_term.c
@@ -1,7 +1,7 @@
-/*	$Id: mdoc_term.c,v 1.151 2013/06/02 18:16:51 schwarze Exp $ */
+/*	$Id: mdoc_term.c,v 1.152 2013/12/22 23:33:52 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2010, 2012 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2010, 2012, 2013 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
@@ -420,6 +420,7 @@ print_mdoc_foot(struct termp *p, const void *arg)
 	p->offset = 0;
 	p->rmargin = (p->maxrmargin - 
 			term_strlen(p, meta->date) + term_len(p, 1)) / 2;
+	p->trailspace = 1;
 	p->flags |= TERMP_NOSPACE | TERMP_NOBREAK;
 
 	term_word(p, meta->os);
@@ -434,6 +435,7 @@ print_mdoc_foot(struct termp *p, const void *arg)
 
 	p->offset = p->rmargin;
 	p->rmargin = p->maxrmargin;
+	p->trailspace = 0;
 	p->flags &= ~TERMP_NOBREAK;
 	p->flags |= TERMP_NOSPACE;
 
@@ -485,6 +487,7 @@ print_mdoc_head(struct termp *p, const void *arg)
 	titlen = term_strlen(p, title);
 
 	p->flags |= TERMP_NOBREAK | TERMP_NOSPACE;
+	p->trailspace = 1;
 	p->offset = 0;
 	p->rmargin = 2 * (titlen+1) + buflen < p->maxrmargin ?
 	    (p->maxrmargin -
@@ -503,6 +506,7 @@ print_mdoc_head(struct termp *p, const void *arg)
 	term_flushln(p);
 
 	p->flags &= ~TERMP_NOBREAK;
+	p->trailspace = 0;
 	if (p->rmargin + titlen <= p->maxrmargin) {
 		p->flags |= TERMP_NOSPACE;
 		p->offset = p->rmargin;
@@ -790,13 +794,13 @@ termp_it_pre(DECL_ARGS)
 	case (LIST_dash):
 		/* FALLTHROUGH */
 	case (LIST_hyphen):
-		if (MDOC_HEAD == n->type)
-			p->flags |= TERMP_NOBREAK;
+		if (MDOC_HEAD != n->type)
+			break;
+		p->flags |= TERMP_NOBREAK;
+		p->trailspace = 1;
 		break;
 	case (LIST_hang):
-		if (MDOC_HEAD == n->type)
-			p->flags |= TERMP_NOBREAK;
-		else
+		if (MDOC_HEAD != n->type)
 			break;
 
 		/*
@@ -808,16 +812,18 @@ termp_it_pre(DECL_ARGS)
 		if (n->next->child && 
 				(MDOC_Bl == n->next->child->tok ||
 				 MDOC_Bd == n->next->child->tok))
-			p->flags &= ~TERMP_NOBREAK;
-		else
-			p->flags |= TERMP_HANG;
+			break;
+
+		p->flags |= TERMP_NOBREAK | TERMP_HANG;
+		p->trailspace = 1;
 		break;
 	case (LIST_tag):
-		if (MDOC_HEAD == n->type)
-			p->flags |= TERMP_NOBREAK | TERMP_TWOSPACE;
-
 		if (MDOC_HEAD != n->type)
 			break;
+
+		p->flags |= TERMP_NOBREAK;
+		p->trailspace = 2;
+
 		if (NULL == n->next || NULL == n->next->child)
 			p->flags |= TERMP_DANGLE;
 		break;
@@ -825,15 +831,20 @@ termp_it_pre(DECL_ARGS)
 		if (MDOC_HEAD == n->type)
 			break;
 
-		if (NULL == n->next)
+		if (NULL == n->next) {
 			p->flags &= ~TERMP_NOBREAK;
-		else
+			p->trailspace = 0;
+		} else {
 			p->flags |= TERMP_NOBREAK;
+			p->trailspace = 1;
+		}
 
 		break;
 	case (LIST_diag):
-		if (MDOC_HEAD == n->type)
-			p->flags |= TERMP_NOBREAK;
+		if (MDOC_HEAD != n->type)
+			break;
+		p->flags |= TERMP_NOBREAK;
+		p->trailspace = 1;
 		break;
 	default:
 		break;
@@ -985,8 +996,8 @@ termp_it_post(DECL_ARGS)
 
 	p->flags &= ~TERMP_DANGLE;
 	p->flags &= ~TERMP_NOBREAK;
-	p->flags &= ~TERMP_TWOSPACE;
 	p->flags &= ~TERMP_HANG;
+	p->trailspace = 0;
 }
 
 
@@ -1019,6 +1030,7 @@ termp_nm_pre(DECL_ARGS)
 
 	if (MDOC_HEAD == n->type && n->next->child) {
 		p->flags |= TERMP_NOSPACE | TERMP_NOBREAK;
+		p->trailspace = 1;
 		p->rmargin = p->offset + term_len(p, 1);
 		if (NULL == n->child) {
 			p->rmargin += term_strlen(p, meta->name);
@@ -1047,6 +1059,7 @@ termp_nm_post(DECL_ARGS)
 	if (MDOC_HEAD == n->type && n->next->child) {
 		term_flushln(p);
 		p->flags &= ~(TERMP_NOBREAK | TERMP_HANG);
+		p->trailspace = 0;
 	} else if (MDOC_BODY == n->type && n->child)
 		term_flushln(p);
 }