Fix MessageR, setting audience to the one specified in the Create activity

src/Vervis/Handler/Discussion.hs

@@ -43,6 +43,7 @@ import Yesod.Form.Types (FormResult (..))
 import Yesod.Persist.Core (runDB, get404, getBy404)
 
 import Data.Aeson.Encode.Pretty.ToEncoding
+import Database.Persist.JSON
 import Network.FedURI
 import Web.ActivityPub
 import Yesod.Auth.Unverified
@@ -147,6 +148,8 @@ getDiscussionMessage shr lmid = do
                     rs <- getJust $ remoteMessageAuthor rmParent
                     i <- getJust $ remoteActorInstance rs
                     return $ l2f (instanceHost i) (remoteActorIdent rs)
+        ob <- getJust $ localMessageCreate lm
+        let activity = docValue $ persistJSONValue $ outboxItemActivity ob
 
         host <- getsYesod $ appInstanceHost . appSettings
         route2local <- getEncodeRouteLocal
@@ -154,7 +157,10 @@ getDiscussionMessage shr lmid = do
         return $ Doc host Note
             { noteId        = Just $ route2local $ MessageR shr lmhid
             , noteAttrib    = route2local $ SharerR shr
-            , noteAudience  = error "TODO noteAudience"
+            , noteAudience  =
+                case activitySpecific activity of
+                    CreateActivity (Create note) -> noteAudience note
+                    _ -> error $ "lmid#" ++ show (fromSqlKey lmid) ++ "'s create isn't a Create activity!"
             , noteReplyTo   = Just $ fromMaybe uContext muParent
             , noteContext   = Just uContext
             , notePublished = Just $ messageCreated m