Add a new term_flushln() flag TERMP_BRIND (if break, then indent)

to control indentation of continuation lines in TERMP_NOBREAK mode.
In the past, this was always on; continue using it
for .Bl, .Nm, .Fn, .Fo, and .HP, but no longer for .IP and .TP.

I looked at this because sthen@ reported the issue in a manual
of a Perl module from ports, but it affects base, too: This patch
reduces groff-mandoc differences in base by more than 15%.

4 files changed, 46 insertions, 51 deletions

diff --git a/usr.bin/mandoc/man_term.c b/usr.bin/mandoc/man_term.c
index 1028eabd5c7..4d39aa4469f 100644
--- a/usr.bin/mandoc/man_term.c
+++ b/usr.bin/mandoc/man_term.c
@@ -1,4 +1,4 @@
-/*	$Id: man_term.c,v 1.98 2014/03/30 21:27:59 schwarze Exp $ */
+/*	$Id: man_term.c,v 1.99 2014/04/08 07:13:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2014 Ingo Schwarze <schwarze@openbsd.org>
@@ -274,7 +274,7 @@ pre_literal(DECL_ARGS)
 		p->offset = p->rmargin;
 		p->rmargin = p->maxrmargin;
 		p->trailspace = 0;
-		p->flags &= ~TERMP_NOBREAK;
+		p->flags &= ~(TERMP_NOBREAK | TERMP_BRIND);
 		p->flags |= TERMP_NOSPACE;
 	}
 
@@ -543,7 +543,7 @@ pre_HP(DECL_ARGS)
 	}
 
 	if ( ! (MANT_LITERAL & mt->fl)) {
-		p->flags |= TERMP_NOBREAK;
+		p->flags |= TERMP_NOBREAK | TERMP_BRIND;
 		p->trailspace = 2;
 	}
 
@@ -578,7 +578,7 @@ post_HP(DECL_ARGS)
 	switch (n->type) {
 	case (MAN_BODY):
 		term_newln(p);
-		p->flags &= ~TERMP_NOBREAK;
+		p->flags &= ~(TERMP_NOBREAK | TERMP_BRIND);
 		p->trailspace = 0;
 		p->offset = mt->offset;
 		p->rmargin = p->maxrmargin;
diff --git a/usr.bin/mandoc/mdoc_term.c b/usr.bin/mandoc/mdoc_term.c
index ff4a59b6d82..804e4c86de3 100644
--- a/usr.bin/mandoc/mdoc_term.c
+++ b/usr.bin/mandoc/mdoc_term.c
@@ -1,4 +1,4 @@
-/*	$Id: mdoc_term.c,v 1.164 2014/04/08 04:40:29 schwarze Exp $ */
+/*	$Id: mdoc_term.c,v 1.165 2014/04/08 07:13:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010, 2012, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
@@ -815,14 +815,14 @@ termp_it_pre(DECL_ARGS)
 				 MDOC_Bd == n->next->child->tok))
 			break;
 
-		p->flags |= TERMP_NOBREAK | TERMP_HANG;
+		p->flags |= TERMP_NOBREAK | TERMP_BRIND | TERMP_HANG;
 		p->trailspace = 1;
 		break;
 	case (LIST_tag):
 		if (MDOC_HEAD != n->type)
 			break;
 
-		p->flags |= TERMP_NOBREAK;
+		p->flags |= TERMP_NOBREAK | TERMP_BRIND;
 		p->trailspace = 2;
 
 		if (NULL == n->next || NULL == n->next->child)
@@ -844,7 +844,7 @@ termp_it_pre(DECL_ARGS)
 	case (LIST_diag):
 		if (MDOC_HEAD != n->type)
 			break;
-		p->flags |= TERMP_NOBREAK;
+		p->flags |= TERMP_NOBREAK | TERMP_BRIND;
 		p->trailspace = 1;
 		break;
 	default:
@@ -998,9 +998,8 @@ termp_it_post(DECL_ARGS)
 	 * has munged them in the meanwhile.
 	 */
 
-	p->flags &= ~TERMP_DANGLE;
-	p->flags &= ~TERMP_NOBREAK;
-	p->flags &= ~TERMP_HANG;
+	p->flags &= ~(TERMP_NOBREAK | TERMP_BRIND |
+			TERMP_DANGLE | TERMP_HANG);
 	p->trailspace = 0;
 }
 
@@ -1037,7 +1036,7 @@ termp_nm_pre(DECL_ARGS)
 		synopsis_pre(p, n->parent);
 
 	if (MDOC_HEAD == n->type && n->next->child) {
-		p->flags |= TERMP_NOSPACE | TERMP_NOBREAK;
+		p->flags |= TERMP_NOSPACE | TERMP_NOBREAK | TERMP_BRIND;
 		p->trailspace = 1;
 		p->rmargin = p->offset + term_len(p, 1);
 		if (NULL == n->child) {
@@ -1068,7 +1067,7 @@ termp_nm_post(DECL_ARGS)
 		p->flags &= ~(TERMP_KEEP | TERMP_PREKEEP);
 	} else if (MDOC_HEAD == n->type && n->next->child) {
 		term_flushln(p);
-		p->flags &= ~(TERMP_NOBREAK | TERMP_HANG);
+		p->flags &= ~(TERMP_NOBREAK | TERMP_BRIND | TERMP_HANG);
 		p->trailspace = 0;
 	} else if (MDOC_BODY == n->type && n->child)
 		term_flushln(p);
@@ -1557,7 +1556,7 @@ termp_fn_pre(DECL_ARGS)
 	if (pretty) {
 		rmargin = p->rmargin;
 		p->rmargin = p->offset + term_len(p, 4);
-		p->flags |= TERMP_NOBREAK | TERMP_HANG;
+		p->flags |= TERMP_NOBREAK | TERMP_BRIND | TERMP_HANG;
 	}
 
 	assert(MDOC_TEXT == n->type);
@@ -1567,7 +1566,7 @@ termp_fn_pre(DECL_ARGS)
 
 	if (pretty) {
 		term_flushln(p);
-		p->flags &= ~(TERMP_NOBREAK | TERMP_HANG);
+		p->flags &= ~(TERMP_NOBREAK | TERMP_BRIND | TERMP_HANG);
 		p->offset = p->rmargin;
 		p->rmargin = rmargin;
 	}
@@ -2059,14 +2058,16 @@ termp_fo_pre(DECL_ARGS)
 		if (pretty) {
 			rmargin = p->rmargin;
 			p->rmargin = p->offset + term_len(p, 4);
-			p->flags |= TERMP_NOBREAK | TERMP_HANG;
+			p->flags |= TERMP_NOBREAK | TERMP_BRIND |
+					TERMP_HANG;
 		}
 		p->flags |= TERMP_NOSPACE;
 		term_word(p, "(");
 		p->flags |= TERMP_NOSPACE;
 		if (pretty) {
 			term_flushln(p);
-			p->flags &= ~(TERMP_NOBREAK | TERMP_HANG);
+			p->flags &= ~(TERMP_NOBREAK | TERMP_BRIND |
+					TERMP_HANG);
 			p->offset = p->rmargin;
 			p->rmargin = rmargin;
 		}
diff --git a/usr.bin/mandoc/term.c b/usr.bin/mandoc/term.c
index de9f85c9ad6..30ed864bd7a 100644
--- a/usr.bin/mandoc/term.c
+++ b/usr.bin/mandoc/term.c
@@ -1,4 +1,4 @@
-/*	$Id: term.c,v 1.81 2014/04/05 21:17:48 schwarze Exp $ */
+/*	$Id: term.c,v 1.82 2014/04/08 07:13:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2014 Ingo Schwarze <schwarze@openbsd.org>
@@ -68,34 +68,27 @@ term_end(struct termp *p)
 }
 
 /*
- * Flush a line of text.  A "line" is loosely defined as being something
- * that should be followed by a newline, regardless of whether it's
- * broken apart by newlines getting there.  A line can also be a
- * fragment of a columnar list (`Bl -tag' or `Bl -column'), which does
- * not have a trailing newline.
- *
+ * Flush a chunk of text.  By default, break the output line each time
+ * the right margin is reached, and continue output on the next line
+ * at the same offset as the chunk itself.  By default, also break the
+ * output line at the end of the chunk.
  * The following flags may be specified:
  *
- *  - TERMP_NOBREAK: this is the most important and is used when making
- *    columns.  In short: don't print a newline and instead expect the
- *    next call to do the padding up to the start of the next column.
- *    p->trailspace may be set to 0, 1, or 2, depending on how many
- *    space characters are required at the end of the column.
- *
- *  - TERMP_DANGLE: don't newline when TERMP_NOBREAK is specified and
- *    the line is overrun, and don't pad-right if it's underrun.
- *
- *  - TERMP_HANG: like TERMP_DANGLE, but doesn't newline when
- *    overrunning, instead save the position and continue at that point
- *    when the next invocation.
- *
- *  In-line line breaking:
- *
- *  If TERMP_NOBREAK is specified and the line overruns the right
- *  margin, it will break and pad-right to the right margin after
- *  writing.  If maxrmargin is violated, it will break and continue
- *  writing from the right-margin, which will lead to the above scenario
- *  upon exit.  Otherwise, the line will break at the right margin.
+ *  - TERMP_NOBREAK: Do not break the output line at the right margin,
+ *    but only at the max right margin.  Also, do not break the output
+ *    line at the end of the chunk, such that the next call can pad to
+ *    the next column.  However, if less than p->trailspace blanks,
+ *    which can be 0, 1, or 2, remain to the right margin, the line
+ *    will be broken.
+ *  - TERMP_BRIND: If the chunk does not fit and the output line has
+ *    to be broken, start the next line at the right margin instead
+ *    of at the offset.  Used together with TERMP_NOBREAK for the tags
+ *    in various kinds of tagged lists.
+ *  - TERMP_DANGLE: Do not break the output line at the right margin,
+ *    append the next chunk after it even if this one is too long.
+ *    To be used together with TERMP_NOBREAK.
+ *  - TERMP_HANG: Like TERMP_DANGLE, and also suppress padding before
+ *    the next chunk if this column is not full.
  */
 void
 term_flushln(struct termp *p)
@@ -197,7 +190,7 @@ term_flushln(struct termp *p)
 			vend -= vis;
 			(*p->endline)(p);
 			p->viscol = 0;
-			if (TERMP_NOBREAK & p->flags) {
+			if (TERMP_BRIND & p->flags) {
 				vbl = p->rmargin;
 				vend += p->rmargin - p->offset;
 			} else
diff --git a/usr.bin/mandoc/term.h b/usr.bin/mandoc/term.h
index 6a63dd084e7..10cf8a330f7 100644
--- a/usr.bin/mandoc/term.h
+++ b/usr.bin/mandoc/term.h
@@ -1,4 +1,4 @@
-/*	$Id: term.h,v 1.43 2014/03/30 21:27:59 schwarze Exp $ */
+/*	$Id: term.h,v 1.44 2014/04/08 07:13:01 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011, 2012, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
@@ -77,11 +77,12 @@ struct	termp {
 #define	TERMP_PREKEEP	 (1 << 6)	/* ...starting with the next one. */
 #define	TERMP_SKIPCHAR	 (1 << 7)	/* Skip the next character. */
 #define	TERMP_NOBREAK	 (1 << 8)	/* See term_flushln(). */
-#define	TERMP_DANGLE	 (1 << 9)	/* See term_flushln(). */
-#define	TERMP_HANG	 (1 << 10)	/* See term_flushln(). */
-#define	TERMP_NOSPLIT	 (1 << 11)	/* See termp_an_pre/post(). */
-#define	TERMP_SPLIT	 (1 << 12)	/* See termp_an_pre/post(). */
-#define	TERMP_ANPREC	 (1 << 13)	/* See termp_an_pre(). */
+#define	TERMP_BRIND	 (1 << 9)	/* See term_flushln(). */
+#define	TERMP_DANGLE	 (1 << 10)	/* See term_flushln(). */
+#define	TERMP_HANG	 (1 << 11)	/* See term_flushln(). */
+#define	TERMP_NOSPLIT	 (1 << 12)	/* See termp_an_pre/post(). */
+#define	TERMP_SPLIT	 (1 << 13)	/* See termp_an_pre/post(). */
+#define	TERMP_ANPREC	 (1 << 14)	/* See termp_an_pre(). */
 	int		 *buf;		/* Output buffer. */
 	enum termenc	  enc;		/* Type of encoding. */
 	struct mchars	 *symtab;	/* Encoded-symbol table. */