Remove the terminal frontend flag TERMP_NOLPAD.

In columnated contexts (.Bl -column, .Bl -tag, .IP, .TP, .HP etc.), do not
pad after writing a column.  Instead, always pad before writing content.

In itself, this change avoids:
 - writing trailing whitespace in some situations
 - with .fi/.nf in .HP, breaking lines that were already padded

It allows several bugfixes included in this patch:
 - Do not count backspace as a character with positive width.
 - Set up proper indentation when encountering .fi/.nf in .HP.
 - Adjust the .HP indentation width to what groff does.
 - Never unlimit the right margin unless in the final column.

This reduces the groff/mandoc-differences in base by nearly 20%,
from 89k to 72k lines of diffs.

ok kristaps@

1 files changed, 23 insertions, 13 deletions

diff --git a/usr.bin/mandoc/man_term.c b/usr.bin/mandoc/man_term.c
index f976892aaa6..f6649d314d8 100644
--- a/usr.bin/mandoc/man_term.c
+++ b/usr.bin/mandoc/man_term.c
@@ -1,4 +1,4 @@
-/*	$Id: man_term.c,v 1.71 2011/09/18 10:25:28 schwarze Exp $ */
+/*	$Id: man_term.c,v 1.72 2011/09/19 22:36:11 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010, 2011 Ingo Schwarze <schwarze@openbsd.org>
@@ -241,6 +241,18 @@ pre_literal(DECL_ARGS)
 	else
 		mt->fl &= ~MANT_LITERAL;
 
+	/*
+	 * Unlike .IP and .TP, .HP does not have a HEAD.
+	 * So in case a second call to term_flushln() is needed,
+	 * indentation has to be set up explicitly.
+	 */
+	if (MAN_HP == n->parent->tok && p->rmargin < p->maxrmargin) {
+		p->offset = p->rmargin + 1;
+		p->rmargin = p->maxrmargin;
+		p->flags &= ~(TERMP_NOBREAK | TERMP_TWOSPACE);
+		p->flags |= TERMP_NOSPACE;
+	}
+
 	return(0);
 }
 
@@ -427,7 +439,7 @@ pre_sp(DECL_ARGS)
 static int
 pre_HP(DECL_ARGS)
 {
-	size_t			 len;
+	size_t			 len, one;
 	int			 ival;
 	const struct man_node	*nn;
 
@@ -452,8 +464,11 @@ pre_HP(DECL_ARGS)
 		if ((ival = a2width(p, nn->string)) >= 0)
 			len = (size_t)ival;
 
-	if (0 == len)
-		len = term_len(p, 1);
+	one = term_len(p, 1);
+	if (len > one)
+		len -= one;
+	else
+		len = one;
 
 	p->offset = mt->offset;
 	p->rmargin = mt->offset + len;
@@ -516,7 +531,6 @@ pre_IP(DECL_ARGS)
 
 	switch (n->type) {
 	case (MAN_BODY):
-		p->flags |= TERMP_NOLPAD;
 		p->flags |= TERMP_NOSPACE;
 		break;
 	case (MAN_HEAD):
@@ -587,7 +601,6 @@ post_IP(DECL_ARGS)
 		break;
 	case (MAN_BODY):
 		term_newln(p);
-		p->flags &= ~TERMP_NOLPAD;
 		break;
 	default:
 		break;
@@ -608,7 +621,6 @@ pre_TP(DECL_ARGS)
 		p->flags |= TERMP_NOBREAK;
 		break;
 	case (MAN_BODY):
-		p->flags |= TERMP_NOLPAD;
 		p->flags |= TERMP_NOSPACE;
 		break;
 	case (MAN_BLOCK):
@@ -677,7 +689,6 @@ post_TP(DECL_ARGS)
 		break;
 	case (MAN_BODY):
 		term_newln(p);
-		p->flags &= ~TERMP_NOLPAD;
 		break;
 	default:
 		break;
@@ -878,7 +889,7 @@ print_man_node(DECL_ARGS)
 		 * -man doesn't have nested macros, we don't need to be
 		 * more specific than this.
 		 */
-		if (MANT_LITERAL & mt->fl && 
+		if (MANT_LITERAL & mt->fl && ! (TERMP_NOBREAK & p->flags) &&
 				(NULL == n->next || 
 				 n->next->line > n->line)) {
 			rm = p->rmargin;
@@ -886,7 +897,6 @@ print_man_node(DECL_ARGS)
 			p->rmargin = p->maxrmargin = TERM_MAXMARGIN;
 			p->flags |= TERMP_NOSPACE;
 			term_flushln(p);
-			p->flags &= ~TERMP_NOLPAD;
 			p->rmargin = rm;
 			p->maxrmargin = rmax;
 		}
@@ -968,7 +978,7 @@ print_man_foot(struct termp *p, const void *arg)
 		term_word(p, "");
 	term_flushln(p);
 
-	p->flags |= TERMP_NOLPAD | TERMP_NOSPACE;
+	p->flags |= TERMP_NOSPACE;
 	p->offset = p->rmargin;
 	p->rmargin = p->maxrmargin;
 	p->flags &= ~TERMP_NOBREAK;
@@ -1015,7 +1025,7 @@ print_man_head(struct termp *p, const void *arg)
 	term_word(p, title);
 	term_flushln(p);
 
-	p->flags |= TERMP_NOLPAD | TERMP_NOSPACE;
+	p->flags |= TERMP_NOSPACE;
 	p->offset = p->rmargin;
 	p->rmargin = p->offset + buflen + titlen < p->maxrmargin ?
 	    p->maxrmargin - titlen : p->maxrmargin;
@@ -1025,7 +1035,7 @@ print_man_head(struct termp *p, const void *arg)
 
 	p->flags &= ~TERMP_NOBREAK;
 	if (p->rmargin + titlen <= p->maxrmargin) {
-		p->flags |= TERMP_NOLPAD | TERMP_NOSPACE;
+		p->flags |= TERMP_NOSPACE;
 		p->offset = p->rmargin;
 		p->rmargin = p->maxrmargin;
 		term_word(p, title);