Ignore non-existent /etc/hosts

Fixes #64

Author: sionescu

src/sockets/namedb/hosts.lisp

@@ -52,8 +52,9 @@
              (destructuring-bind (address cname &rest aliases) tokens
                (push (make-host cname (ensure-address address) aliases)
                      hosts))))
-      (map-etc-file (lambda (tokens) (ignore-errors (parse-one-line tokens)))
-                    file)
+      (alexandria:ignore-some-conditions (file-error)
+        (map-etc-file (lambda (tokens) (ignore-errors (parse-one-line tokens)))
+                      file))
       (nreverse hosts))))
 
 (defun search-host-by-name (name ipv6)

tests/sockets.lisp

@@ -187,6 +187,9 @@
 (defparameter *google-ns*
   (list #/ip/8.8.8.8 #/ip/8.8.4.4))
 
+(test (missing-hosts-file :compile-at :definition-time)
+  (is-false (iolib/sockets::parse-/etc/hosts "/foo/no-such-file")))
+
 #-no-internet-available
 (test (lookup-hostname.1 :compile-at :definition-time)
   (is (equalp (multiple-value-bind (address addresses truename)