diff --git a/arg.c b/arg.c
index a1508528..d4d31210 100644
--- a/arg.c
+++ b/arg.c
@@ -1,4 +1,4 @@
-/* $Id: arg.c,v 1.5 2008-08-28 17:45:25 nicm Exp $ */
+/* $Id: arg.c,v 1.6 2009-06-25 15:25:45 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -76,7 +76,7 @@ arg_parse_client(const char *arg)
 
 		/* Trim a trailing : if any from the argument. */
 		n = strlen(arg2);
-		if (arg2[n - 1] == ':')
+		if (n && arg2[n - 1] == ':')
 			arg2[n - 1] = '\0';
 
 		/* Try and look up the client name. */
@@ -101,7 +101,7 @@ arg_parse_session(const char *arg)
 
 		/* Trim a trailing : if any from the argument. */
 		n = strlen(arg2);
-		if (arg2[n - 1] == ':')
+		if (n && arg2[n - 1] == ':')
 			arg2[n - 1] = '\0';
 
 		/* See if the argument matches a session. */
diff --git a/attributes.c b/attributes.c
index 24744481..259b7434 100644
--- a/attributes.c
+++ b/attributes.c
@@ -1,4 +1,4 @@
-/* $Id: attributes.c,v 1.1 2009-01-27 20:22:33 nicm Exp $ */
+/* $Id: attributes.c,v 1.2 2009-06-25 15:25:45 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Joshua Elsasser <josh@elsasser.org>
@@ -45,7 +45,8 @@ attributes_tostring(u_char ch)
 		strlcat(buf, "hidden,", sizeof (buf));
 	if (ch & GRID_ATTR_ITALICS)
 		strlcat(buf, "italics,", sizeof (buf));
-	*(strrchr(buf, ',')) = '\0';
+	if (*buf)
+		*(strrchr(buf, ',')) = '\0';
 
 	return (buf);
 }
diff --git a/client-msg.c b/client-msg.c
index 182b26f2..14600421 100644
--- a/client-msg.c
+++ b/client-msg.c
@@ -1,4 +1,4 @@
-/* $Id: client-msg.c,v 1.18 2009-01-21 22:47:31 nicm Exp $ */
+/* $Id: client-msg.c,v 1.19 2009-06-25 15:25:45 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -73,7 +73,7 @@ client_msg_dispatch(struct client_ctx *cctx, char **error)
 int
 client_msg_fn_error(struct hdr *hdr, struct client_ctx *cctx, char **error)
 {
-	if (hdr->size > SIZE_MAX - 1)
+	if (hdr->size == SIZE_MAX)
 		fatalx("bad MSG_ERROR size");
 
 	*error = xmalloc(hdr->size + 1);