Surprisingly, groff does not support scaling units in .Bl -column

column width specifiers, so stop supporting them, too.
As a side effect, this fixes an assertion failure that tb@ found
with afl(1), triggered by: .Bl -column -4n

4 files changed, 19 insertions, 13 deletions

diff --git a/NEWS b/NEWS
index 687c19b5..9f3071c0 100644
--- a/NEWS
+++ b/NEWS
@@ -1,4 +1,4 @@
-$Id: NEWS,v 1.19 2017/02/12 14:19:01 schwarze Exp $
+$Id: NEWS,v 1.20 2017/02/16 14:38:12 schwarze Exp $
 
 This file lists the most important changes in the mdocml.bsd.lv distribution.
 
@@ -65,6 +65,8 @@ Changes in version 1.14.1, released on February XXX, 2017
    for empty matrices and empty square roots.
  * mdoc(7): Fix an assertion failure for a .Bd without a type that
    breaks another block.
+ * mdoc(7): Fix an assertion failure that happened for some .Bl -column
+   lists containing a column width of "-4n", "-3n", or "-2n".
  * mdoc(7): Fix an assertion failure caused by .Bl -column without .It
    but containing eqn(7) or tbl(7) code.
  * roff(7): Fix an assertion failure caused by \z\[u00FF] with -Tps/-Tpdf.
diff --git a/mdoc.7 b/mdoc.7
index ce4bd92f..6d958877 100644
--- a/mdoc.7
+++ b/mdoc.7
@@ -1,4 +1,4 @@
-.\"	$Id: mdoc.7,v 1.261 2017/02/05 22:30:29 schwarze Exp $
+.\"	$Id: mdoc.7,v 1.262 2017/02/16 14:38:12 schwarze Exp $
 .\"
 .\" Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
 .\" Copyright (c) 2010, 2011, 2013-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -15,7 +15,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: February 5 2017 $
+.Dd $Mdocdate: February 16 2017 $
 .Dt MDOC 7
 .Os
 .Sh NAME
@@ -974,10 +974,8 @@ argument.
 A columnated list.
 The
 .Fl width
-argument has no effect; instead, each argument specifies the width
-of one column, using either the scaling width syntax described in
-.Xr roff 7
-or the string length of the argument.
+argument has no effect; instead, the string length of each argument
+specifies the width of one column.
 If the first line of the body of a
 .Fl column
 list is not an
diff --git a/mdoc_term.c b/mdoc_term.c
index 398fc3f5..bc125f29 100644
--- a/mdoc_term.c
+++ b/mdoc_term.c
@@ -1,4 +1,4 @@
-/*	$Id: mdoc_term.c,v 1.344 2017/02/16 03:00:23 schwarze Exp $ */
+/*	$Id: mdoc_term.c,v 1.345 2017/02/16 14:38:12 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010, 2012-2017 Ingo Schwarze <schwarze@openbsd.org>
@@ -606,6 +606,7 @@ termp_ll_pre(DECL_ARGS)
 static int
 termp_it_pre(DECL_ARGS)
 {
+	struct roffsu		su;
 	char			buf[24];
 	const struct roff_node *bl, *nn;
 	size_t			ncols, dcol;
@@ -683,9 +684,12 @@ termp_it_pre(DECL_ARGS)
 
 		for (i = 0, nn = n->prev;
 		    nn->prev && i < (int)ncols;
-		    nn = nn->prev, i++)
-			offset += dcol + a2width(p,
-			    bl->norm->Bl.cols[i]);
+		    nn = nn->prev, i++) {
+			SCALE_HS_INIT(&su,
+			    term_strlen(p, bl->norm->Bl.cols[i]));
+			su.scale /= term_strlen(p, "0");
+			offset += term_hspan(p, &su) / 24 + dcol;
+		}
 
 		/*
 		 * When exceeding the declared number of columns, leave
@@ -700,7 +704,9 @@ termp_it_pre(DECL_ARGS)
 		 * Use the declared column widths, extended as explained
 		 * in the preceding paragraph.
 		 */
-		width = a2width(p, bl->norm->Bl.cols[i]) + dcol;
+		SCALE_HS_INIT(&su, term_strlen(p, bl->norm->Bl.cols[i]));
+		su.scale /= term_strlen(p, "0");
+		width = term_hspan(p, &su) / 24 + dcol;
 		break;
 	default:
 		if (NULL == bl->norm->Bl.width)
diff --git a/regress/mdoc/Bl/breakingTa.in b/regress/mdoc/Bl/breakingTa.in
index ca8e5769..80192b6c 100644
--- a/regress/mdoc/Bl/breakingTa.in
+++ b/regress/mdoc/Bl/breakingTa.in
@@ -7,7 +7,7 @@
 .Sh DESCRIPTION
 .\" Crashed before mdoc_macro.c OpenBSD rev. 1.172
 initial text
-.Bl -column 6n 6n
+.Bl -column 123456 123456
 .It it Aq aq Ta ta Bo bo bc
 .Bc Pq pq
 .El