Index: files.c
--- files.c.orig
+++ files.c
@@ -334,11 +334,7 @@ mkfilename(struct place *place, const char *dir, const
 
 	rlen = dlen + (needslash ? 1 : 0) + flen;
 	ret = domalloc(rlen + 1);
-	strcpy(ret, dir);
-	if (needslash) {
-		strcat(ret, "/");
-	}
-	strcat(ret, file);
+	snprintf(ret, rlen+1, "%s%s%s", dir, needslash ? "/" : "", file);
 	return ret;
 }
 
@@ -351,7 +347,7 @@ file_tryopen(const char *file)
 	/* XXX check for non-regular files */
 
 	fd = open(file, O_RDONLY);
-	if (fd < 0) {
+	if (fd == -1) {
 		if (errno != ENOENT && errno != ENOTDIR) {
 			complain(NULL, "%s: %s", file, strerror(errno));
 		}