Removed stipulation that an empty `Bd -offset' will default to 6n. Not

sure where this came about.  Added regression tests to convince myself
that this is so.  Also consolidated COMPATIBILITY notes regarding `Bd'.
Added COMPATIBILITY note to the effect that old groff pukes on `Bd
-compact -ragged' (regression test will fail on old groff).

7 files changed, 80 insertions, 33 deletions

diff --git a/main.c b/main.c
index f8e2e99f..1996712b 100644
--- a/main.c
+++ b/main.c
@@ -109,6 +109,7 @@ static	const char * const	mandocerrs[MANDOCERR_MAX] = {
 	"unterminated quoted string",
 	"argument requires the width argument",
 	"superfluous width argument",
+	"ignoring argument",
 	"bad date argument",
 	"bad width argument",
 	"unknown manual section",
diff --git a/mandoc.h b/mandoc.h
index 83154f0d..74fc3a27 100644
--- a/mandoc.h
+++ b/mandoc.h
@@ -36,7 +36,9 @@ enum	mandocerr {
 	MANDOCERR_BADESCAPE, /* bad escape sequence */
 	MANDOCERR_BADQUOTE, /* unterminated quoted string */
 	MANDOCERR_NOWIDTHARG, /* argument requires the width argument */
+	/* FIXME: merge with MANDOCERR_IGNARGV. */
 	MANDOCERR_WIDTHARG, /* superfluous width argument */
+	MANDOCERR_IGNARGV, /* macro ignoring argv */
 	MANDOCERR_BADDATE, /* bad date argument */
 	MANDOCERR_BADWIDTH, /* bad width argument */
 	MANDOCERR_BADMSEC, /* unknown manual section */
diff --git a/mdoc.7 b/mdoc.7
index f2c03c53..1a25d73f 100644
--- a/mdoc.7
+++ b/mdoc.7
@@ -1094,10 +1094,7 @@ As a scaling unit following the syntax described in
 As the calculated string length of the opaque string.
 .El
 .Pp
-If unset, it will revert to the value of
-.Ar 8n
-as described in
-.Sx Scaling Widths .
+If not provided an argument, it will be ignored.
 .It Fl compact
 Do not assert a vertical space before the block.
 .It Fl file Ar file
@@ -2169,11 +2166,8 @@ Heirloom troff, the other significant troff implementation accepting
 .Pp
 .Bl -dash -compact
 .It
-groff supports a
-.Fl file Ar filename
-argument to
-.Sx \&Bd .
-mandoc does not.
+Old groff fails to assert a newline before
+.Sx \&Bd Fl ragged compact .
 .It
 groff behaves inconsistently when encountering
 .Pf non- Sx \&Fa
@@ -2249,16 +2243,15 @@ In quoted literals, groff allowed pair-wise double-quotes to produce a
 standalone double-quote in formatted output.
 This idiosyncratic behaviour is not applicable in mandoc.
 .It
-Display types
+Display offsets
 .Sx \&Bd
-.Fl center
+.Fl offset Ar center
 and
-.Fl right
-are aliases for
-.Fl left
-in mandoc.  Furthermore, the
+.Fl offset Ar right
+are disregarded in mandoc.
+Furthermore, the
 .Fl file Ar file
-argument is ignored.
+argument is not supported in mandoc.
 Lastly, since text is not right-justified in mandoc (or even groff),
 .Fl ragged
 and
diff --git a/mdoc_validate.c b/mdoc_validate.c
index 10316fc4..ed0a4c25 100644
--- a/mdoc_validate.c
+++ b/mdoc_validate.c
@@ -731,23 +731,8 @@ pre_bd(PRE_ARGS)
 				dup = (NULL != n->data.Bd.offs);
 				break;
 			}
-			/*
-			 * If empty, assign it to a sane default, which
-			 * groff stipulates is about 8n.
-			 */
-			/*
-			 * FIXME: remove this.
-			 *
-			 * Where the hell did I get the idea that this
-			 * happens?
-			 */
-			assert(1 == n->args->refcnt);
-			n->args->argv[i].sz++;
-			n->args->argv[i].value = 
-				mandoc_malloc(sizeof(char *));
-			n->args->argv[i].value[0] = 
-				mandoc_strdup("8n");
-			offs = n->args->argv[i].value[0];
+			if ( ! mdoc_nmsg(mdoc, n, MANDOCERR_IGNARGV))
+				return(0);
 			break;
 		case (MDOC_Compact):
 			comp = 1;
diff --git a/regress/mdoc/Bd/bd-compact.in b/regress/mdoc/Bd/bd-compact.in
new file mode 100644
index 00000000..a6cf21db
--- /dev/null
+++ b/regress/mdoc/Bd/bd-compact.in
@@ -0,0 +1,33 @@
+.Dd $Mdocdate$
+.Dt FOO 1
+.Os
+.Sh NAME
+.Nm foo
+.Nd bar
+.Sh DESCRIPTION
+1
+.Bd -literal -compact
+a b
+c d
+.Ed
+2
+1
+.Bd -filled -compact
+a b
+c d
+.Ed
+2
+3
+.\" NOTE: OLD GROFF WILL PUKE HERE, AS IT BUGGILY FORGETS TO EMIT A
+.\" NEWLINE BEFORE THE DISPLAY.
+.Bd -ragged -compact
+a b
+c d
+.Ed
+2
+1
+.Bd -unfilled -compact
+a b
+c d
+.Ed
+2
diff --git a/regress/mdoc/Bd/bd-empty-offset.in b/regress/mdoc/Bd/bd-empty-offset.in
new file mode 100644
index 00000000..1bb6126c
--- /dev/null
+++ b/regress/mdoc/Bd/bd-empty-offset.in
@@ -0,0 +1,31 @@
+.Dd $Mdocdate$
+.Dt FOO 1
+.Os
+.Sh NAME
+.Nm foo
+.Nd bar
+.Sh DESCRIPTION
+1
+.Bd -literal -offset
+a b
+c d
+.Ed
+2
+1
+.Bd -filled -offset
+a b
+c d
+.Ed
+2
+1
+.Bd -ragged -offset
+a b
+c d
+.Ed
+2
+1
+.Bd -unfilled -offset
+a b
+c d
+.Ed
+2
diff --git a/regress/mdoc/Cd/cd.in b/regress/mdoc/Cd/cd.in
index 82e6b0a8..d966aa45 100644
--- a/regress/mdoc/Cd/cd.in
+++ b/regress/mdoc/Cd/cd.in
@@ -9,6 +9,8 @@
 .Cd "it* at isa? port 0x2e"
 .Cd "it* at isa? port 0x2e"
 .Sh DESCRIPTION
+.\" OLD GROFF WILL PUKE ON THIS PART, RENDERING IT JUST AS IT WAS
+.\" RENDERED IN THE SYNOPSIS.
 .Cd "it* at isa? port 0x2e"
 .Cd "it* at isa? port 0x2e"
 .Cd "it* at isa? port 0x2e"