Normalise SYNOPSIS behaviour after I gave up on following groff's

inconsistent behaviour.  In short:

       Some macros are displayed differently in the SYNOPSIS
       section, particularly Nm, Cd, Fd, Fn, Fo, In, Vt, and Ft.
       All of these macros are output on their own line.  If two
       such dissimilar macros are pair-wise invoked (except for Ft
       before Fo or Fn), they are separated by a vertical space,
       unless in the case of Fo, Fn, and Ft, which are always
       separated by vertical space.

Behaviour ok Jason McIntyre, ingo@.  Fallout will be treated
case-by-case.

I had to clear out some regressions that were testing against groff's
stranger behaviours: these will now break, as we don't care about such
invocations.

Also removed the newline for `Cd' invocation in a non-SYNOPSIS context.

1 files changed, 66 insertions, 60 deletions

diff --git a/mdoc_html.c b/mdoc_html.c
index b2d075e4..1c8bb832 100644
--- a/mdoc_html.c
+++ b/mdoc_html.c
@@ -53,6 +53,8 @@ static	void		  print_mdoc(MDOC_ARGS);
 static	void		  print_mdoc_head(MDOC_ARGS);
 static	void		  print_mdoc_node(MDOC_ARGS);
 static	void		  print_mdoc_nodelist(MDOC_ARGS);
+static	void	  	  synopsis_pre(struct html *, 
+				const struct mdoc_node *);
 
 static	void		  a2width(const char *, struct roffsu *);
 static	void		  a2offs(const char *, struct roffsu *);
@@ -84,7 +86,6 @@ static	void		  mdoc_dq_post(MDOC_ARGS);
 static	int		  mdoc_dq_pre(MDOC_ARGS);
 static	int		  mdoc_dv_pre(MDOC_ARGS);
 static	int		  mdoc_fa_pre(MDOC_ARGS);
-static	void		  mdoc_fd_post(MDOC_ARGS);
 static	int		  mdoc_fd_pre(MDOC_ARGS);
 static	int		  mdoc_fl_pre(MDOC_ARGS);
 static	int		  mdoc_fn_pre(MDOC_ARGS);
@@ -159,7 +160,7 @@ static	const struct htmlmdoc mdocs[MDOC_MAX] = {
 	{mdoc_ev_pre, NULL}, /* Ev */ 
 	{mdoc_ex_pre, NULL}, /* Ex */
 	{mdoc_fa_pre, NULL}, /* Fa */ 
-	{mdoc_fd_pre, mdoc_fd_post}, /* Fd */ 
+	{mdoc_fd_pre, NULL}, /* Fd */ 
 	{mdoc_fl_pre, NULL}, /* Fl */
 	{mdoc_fn_pre, NULL}, /* Fn */ 
 	{mdoc_ft_pre, NULL}, /* Ft */ 
@@ -294,6 +295,55 @@ a2width(const char *p, struct roffsu *su)
 
 
 /*
+ * See the same function in mdoc_term.c for documentation.
+ */
+static void
+synopsis_pre(struct html *h, const struct mdoc_node *n)
+{
+	struct roffsu	 su;
+	struct htmlpair	 tag;
+
+	if (NULL == n->prev || SEC_SYNOPSIS != n->sec)
+		return;
+
+	SCALE_VS_INIT(&su, 1);
+	bufcat_su(h, "margin-top", &su);
+	PAIR_STYLE_INIT(&tag, h);
+
+	if (n->prev->tok == n->tok && 
+			MDOC_Fo != n->tok && 
+			MDOC_Ft != n->tok && 
+			MDOC_Fn != n->tok) {
+		print_otag(h, TAG_DIV, 0, NULL);
+		return;
+	}
+
+	switch (n->prev->tok) {
+	case (MDOC_Fd):
+		/* FALLTHROUGH */
+	case (MDOC_Fn):
+		/* FALLTHROUGH */
+	case (MDOC_Fo):
+		/* FALLTHROUGH */
+	case (MDOC_In):
+		/* FALLTHROUGH */
+	case (MDOC_Vt):
+		print_otag(h, TAG_DIV, 1, &tag);
+		break;
+	case (MDOC_Ft):
+		if (MDOC_Fn != n->tok && MDOC_Fo != n->tok) {
+			print_otag(h, TAG_DIV, 1, &tag);
+			break;
+		}
+		/* FALLTHROUGH */
+	default:
+		print_otag(h, TAG_DIV, 0, NULL);
+		break;
+	}
+}
+
+
+/*
  * Calculate the scaling unit passed in an `-offset' argument.  This
  * uses either a native scaling unit (e.g., 1i, 2m), one of a set of
  * predefined strings (indent, etc.), or the string length of the value.
@@ -690,18 +740,12 @@ mdoc_nm_pre(MDOC_ARGS)
 	if (NULL == n->child && NULL == m->name)
 		return(1);
 
-	if (SEC_SYNOPSIS == n->sec && 
-			n->prev && MDOC_LINE & n->flags) {
-		bufcat_style(h, "clear", "both");
-		PAIR_STYLE_INIT(&tag, h);
-		print_otag(h, TAG_BR, 1, &tag);
-	}
+	synopsis_pre(h, n);
 
 	PAIR_CLASS_INIT(&tag, "name");
 	print_otag(h, TAG_SPAN, 1, &tag);
 	if (NULL == n->child)
 		print_text(h, m->name);
-
 	return(1);
 }
 
@@ -1438,7 +1482,7 @@ mdoc_cd_pre(MDOC_ARGS)
 {
 	struct htmlpair	tag;
 
-	print_otag(h, TAG_DIV, 0, NULL);
+	synopsis_pre(h, n);
 	PAIR_CLASS_INIT(&tag, "config");
 	print_otag(h, TAG_SPAN, 1, &tag);
 	return(1);
@@ -1511,20 +1555,13 @@ mdoc_fa_pre(MDOC_ARGS)
 
 
 /* ARGSUSED */
-static void
-mdoc_fd_post(MDOC_ARGS)
-{
-
-	print_otag(h, TAG_BR, 0, NULL);
-}
-
-
-/* ARGSUSED */
 static int
 mdoc_fd_pre(MDOC_ARGS)
 {
 	struct htmlpair	 tag;
 
+	synopsis_pre(h, n);
+
 	PAIR_CLASS_INIT(&tag, "macro");
 	print_otag(h, TAG_SPAN, 1, &tag);
 	return(1);
@@ -1536,18 +1573,12 @@ static int
 mdoc_vt_pre(MDOC_ARGS)
 {
 	struct htmlpair	 tag;
-	struct roffsu	 su;
 
-	if (SEC_SYNOPSIS == n->sec && MDOC_BLOCK == n->type) {
-		if (n->next && MDOC_Vt != n->next->tok) {
-			SCALE_VS_INIT(&su, 1);
-			bufcat_su(h, "margin-bottom", &su);
-			PAIR_STYLE_INIT(&tag, h);
-			print_otag(h, TAG_DIV, 1, &tag);
-		} else
-			print_otag(h, TAG_DIV, 0, NULL);
-		
+	if (MDOC_BLOCK == n->type) {
+		synopsis_pre(h, n);
 		return(1);
+	} else if (MDOC_ELEM == n->type) {
+		synopsis_pre(h, n);
 	} else if (MDOC_HEAD == n->type)
 		return(0);
 
@@ -1563,9 +1594,7 @@ mdoc_ft_pre(MDOC_ARGS)
 {
 	struct htmlpair	 tag;
 
-	if (SEC_SYNOPSIS == n->sec && n->prev)
-		print_otag(h, TAG_BR, 0, NULL);
-
+	synopsis_pre(h, n);
 	PAIR_CLASS_INIT(&tag, "ftype");
 	print_otag(h, TAG_SPAN, 1, &tag);
 	return(1);
@@ -1582,21 +1611,8 @@ mdoc_fn_pre(MDOC_ARGS)
 	char			 nbuf[BUFSIZ];
 	const char		*sp, *ep;
 	int			 sz, i;
-	struct roffsu		 su;
 
-	/* NB: MDOC_LINE has no effect on this macro! */
-	if (SEC_SYNOPSIS == n->sec) {
-		SCALE_HS_INIT(&su, INDENT);
-		bufcat_su(h, "margin-left", &su);
-		su.scale = -su.scale;
-		bufcat_su(h, "text-indent", &su);
-		if (n->prev && MDOC_Ft != n->prev->tok) {
-			SCALE_VS_INIT(&su, 1);
-			bufcat_su(h, "margin-top", &su);
-		} 
-		PAIR_STYLE_INIT(&tag[0], h);
-		print_otag(h, TAG_DIV, 1, tag);
-	}
+	synopsis_pre(h, n);
 
 	/* Split apart into type and name. */
 	assert(n->child->string);
@@ -1782,7 +1798,6 @@ static int
 mdoc_fo_pre(MDOC_ARGS)
 {
 	struct htmlpair	 tag;
-	struct roffsu	 su;
 	struct tag	*t;
 
 	if (MDOC_BODY == n->type) {
@@ -1791,16 +1806,7 @@ mdoc_fo_pre(MDOC_ARGS)
 		h->flags |= HTML_NOSPACE;
 		return(1);
 	} else if (MDOC_BLOCK == n->type) {
-		if (SEC_SYNOPSIS != n->sec)
-			return(1);
-		if (NULL == n->prev || MDOC_Ft == n->prev->tok) {
-			print_otag(h, TAG_DIV, 0, NULL);
-			return(1);
-		}
-		SCALE_VS_INIT(&su, 1);
-		bufcat_su(h, "margin-top", &su);
-		PAIR_STYLE_INIT(&tag, h);
-		print_otag(h, TAG_DIV, 1, &tag);
+		synopsis_pre(h, n);
 		return(1);
 	}
 
@@ -1821,6 +1827,7 @@ mdoc_fo_pre(MDOC_ARGS)
 static void
 mdoc_fo_post(MDOC_ARGS)
 {
+
 	if (MDOC_BODY != n->type)
 		return;
 	h->flags |= HTML_NOSPACE;
@@ -1839,6 +1846,8 @@ mdoc_in_pre(MDOC_ARGS)
 	struct htmlpair		 tag[2];
 	int			 i;
 
+	synopsis_pre(h, n);
+
 	PAIR_CLASS_INIT(&tag[0], "includes");
 	print_otag(h, TAG_SPAN, 1, tag);
 
@@ -1865,9 +1874,6 @@ mdoc_in_pre(MDOC_ARGS)
 	h->flags |= HTML_NOSPACE;
 	print_text(h, ">");
 
-	if (SEC_SYNOPSIS == n->sec && MDOC_LINE & n->flags) 
-		print_otag(h, TAG_BR, 0, NULL);
-
 	return(0);
 }