add assert! helper, prevent vouching for users on list.

framework/libra-framework/sources/ol_sources/not_my_friend.move

@@ -41,12 +41,16 @@ module ol_framework::not_my_friend {
   use std::vector;
   use std::option::{Self, Option};
 
+  friend ol_framework::vouch;
   /// no non-friend list published at this address
   const ENO_LIST_PUBLISHED: u64 = 0;
 
   /// you have not subscribed to any registries of non-friends
   const ENO_REGISTRIES_SUBSCRIBED: u64 = 1;
 
+  /// user is excluded from the other's social graph
+  const ENOT_A_FRIEND: u64 = 2;
+
   /// any user can publish a registry of people they would rather not do
   /// business with.
   // this is alice in the example above
@@ -137,6 +141,21 @@ module ol_framework::not_my_friend {
    }
   }
 
+  //////// ASSERT HELPERS ///////
+  /// aborts tx if maybe_friend is in a subscriber's registries
+  public(friend) fun assert_not_friend(subscriber: address, maybe_friend:
+  address) acquires NotMyFriends, Subscriptions {
+    assert!(is_not_a_friend(subscriber, maybe_friend), error::invalid_state(ENOT_A_FRIEND));
+  }
+
+    /// check in both directions if users have filtered each other out of their
+  /// social graphs
+  public(friend) fun assert_not_friends_duplex(subscriber: address,
+  maybe_friend: address) acquires NotMyFriends, Subscriptions  {
+    assert_not_friend(subscriber, maybe_friend);
+    assert_not_friend(maybe_friend, subscriber);
+  }
+
   //////// GETTERS ////////
   #[view]
   /// checks all registries a user is subscribed to (including own registry) for

framework/libra-framework/sources/ol_sources/vouch.move

@@ -5,6 +5,7 @@ module ol_framework::vouch {
     use ol_framework::ancestry;
     use ol_framework::ol_account;
     use ol_framework::epoch_helper;
+    use ol_framework::not_my_friend;
 
     use diem_framework::system_addresses;
     use diem_framework::transaction_fee;
@@ -66,8 +67,15 @@ module ol_framework::vouch {
     /// will only succesfully vouch if the two are not related by ancestry
     /// prevents spending a vouch that would not be counted.
     /// to add a vouch and ignore this check use insist_vouch
-    public entry fun vouch_for(grantor: &signer, wanna_be_my_friend: address) acquires MyVouches {
-      ancestry::assert_unrelated(signer::address_of(grantor), wanna_be_my_friend);
+    public entry fun vouch_for(grantor: &signer, wanna_be_my_friend: address)
+    acquires MyVouches {
+      let grantor_addr = signer::address_of(grantor);
+
+      // check in both directions if the users are filtering each other from the
+      // social graph
+      not_my_friend::assert_not_friends_duplex(grantor_addr, wanna_be_my_friend);
+
+      ancestry::assert_unrelated(grantor_addr, wanna_be_my_friend);
       vouch_impl(grantor, wanna_be_my_friend);
     }
 
@@ -199,4 +207,4 @@ module ol_framework::vouch {
     public fun test_set_buddies(val: address, buddy_list: vector<address>) acquires MyVouches {
       bulk_set(val, buddy_list);
     }
-  }
+  }