Avoid a memory corruption problem related to "private" in DirPolicy.

This is a posible fix for bug 996.

ChangeLog

@@ -88,6 +88,9 @@ Changes in version 0.2.1.14-rc - 2009-04-12
       patch by Sebastian.
     - Avoid crashing in the presence of certain malformed descriptors.
       Found by lark, and by automated fuzzing.
+    - Avoid crashing when we have "private" in a policy specified in
+      a DirPolicy or SocksPolicy or ReachableAddresses option and we
+      re-load the policy.  May fix bug 996.
 
   o Minor features:
     - When generating circuit events with verbose nicknames for

src/or/policies.c

@@ -411,6 +411,7 @@ load_policy_from_option(config_line_t *config, smartlist_t **policy,
         memcpy(&newp, n, sizeof(newp));
         newp.prt_min = 1;
         newp.prt_max = 65535;
+        newp.is_canonical = 0;
         c = addr_policy_get_canonical_entry(&newp);
         SMARTLIST_REPLACE_CURRENT(*policy, n, c);
         addr_policy_free(n);