Accomodate for groff's crappy behaviour wherein an unrecognised

single-character escape (and ONLY this type of escape) will map back
into itself:

       "If a backslash is followed by a character that does not
	constitute a defined escape sequence the backslash is silently
        ignored and the  character maps to itself."

(From groff.7.)

Found by Jason McIntyre.

1 files changed, 10 insertions, 4 deletions

diff --git a/html.c b/html.c
index 5e19b09c..070562fb 100644
--- a/html.c
+++ b/html.c
@@ -1,4 +1,4 @@
-/*	$Id: html.c,v 1.107 2010/07/16 22:33:30 kristaps Exp $ */
+/*	$Id: html.c,v 1.108 2010/07/21 20:35:03 kristaps Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010 Kristaps Dzonsons <kristaps@bsd.lv>
  *
@@ -88,7 +88,8 @@ static	const char	*const htmlattrs[ATTR_MAX] = {
 	"summary",
 };
 
-static	void		  print_spec(struct html *, const char *, size_t);
+static	void		  print_spec(struct html *, enum roffdeco,
+				const char *, size_t);
 static	void		  print_res(struct html *, const char *, size_t);
 static	void		  print_ctag(struct html *, enum htmltag);
 static	void		  print_doctype(struct html *);
@@ -215,7 +216,7 @@ print_gen_head(struct html *h)
 
 
 static void
-print_spec(struct html *h, const char *p, size_t len)
+print_spec(struct html *h, enum roffdeco d, const char *p, size_t len)
 {
 	int		 cp;
 	const char	*rhs;
@@ -224,6 +225,9 @@ print_spec(struct html *h, const char *p, size_t len)
 	if ((cp = chars_spec2cp(h->symtab, p, len)) > 0) {
 		printf("&#%d;", cp);
 		return;
+	} else if (-1 == cp && DECO_SSPECIAL == d) {
+		fwrite(p, 1, len, stdout);
+		return;
 	} else if (-1 == cp)
 		return;
 
@@ -342,8 +346,10 @@ print_encode(struct html *h, const char *p, int norecurse)
 		case (DECO_RESERVED):
 			print_res(h, seq, sz);
 			break;
+		case (DECO_SSPECIAL):
+			/* FALLTHROUGH */
 		case (DECO_SPECIAL):
-			print_spec(h, seq, sz);
+			print_spec(h, deco, seq, sz);
 			break;
 		case (DECO_PREVIOUS):
 			/* FALLTHROUGH */