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, 6 insertions, 0 deletions

diff --git a/html.c b/html.c
index 82ac8c7f..1e7a88db 100644
--- a/html.c
+++ b/html.c
@@ -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);
 }