Audit strlcpy(3)/strlcat(3) usage.

* Repair three instances of silent truncation, use asprintf(3).
* Change two instances of strlen(3)+malloc(3)+strlcpy(3)+strlcat(3)+...
to use asprintf(3) instead to make them less error prone.
* Cast the return value of four instances where the destination
buffer is known to be large enough to (void).
* Completely remove three useless instances of strlcpy(3)/strlcat(3).
* Mark two places in -Thtml with XXX that can cause information loss
and crashes but are not easy to fix, requiring design changes of
some internal interfaces.
* The file mandocdb.c remains to be audited.

1 files changed, 7 insertions, 1 deletions

diff --git a/html.c b/html.c
index 7319de66..b8a4c445 100644
--- a/html.c
+++ b/html.c
@@ -1,4 +1,4 @@
-/*	$Id: html.c,v 1.156 2014/04/20 16:46:04 schwarze Exp $ */
+/*	$Id: html.c,v 1.157 2014/04/23 16:08:33 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2011, 2012, 2013, 2014 Ingo Schwarze <schwarze@openbsd.org>
@@ -657,6 +657,12 @@ void
 bufcat(struct html *h, const char *p)
 {
 
+	/*
+	 * XXX This is broken and not easy to fix.
+	 * When using the -Oincludes option, buffmt_includes()
+	 * may pass in strings overrunning BUFSIZ, causing a crash.
+	 */
+
 	h->buflen = strlcat(h->buf, p, BUFSIZ);
 	assert(h->buflen < BUFSIZ);
 }