[NGRAMS-REPO]: special case for "pull"

src/Gargantext/API/Ngrams.hs

@@ -749,7 +749,20 @@ tableNgramsPatch :: (HasNgramError err, HasInvalidError err,
                  => CorpusId -> Maybe TabType -> ListId
                  -> Versioned NgramsTablePatch
                  -> m (Versioned NgramsTablePatch)
-tableNgramsPatch _corpusId maybeTabType listId (Versioned p_version p_table) = do
+tableNgramsPatch _corpusId maybeTabType listId (Versioned p_version p_table)
+  | p_table == mempty = do
+      let ngramsType        = ngramsTypeFromTabType maybeTabType
+
+      var <- view repoVar
+      r <- liftIO $ readMVar var
+
+      let
+        q = mconcat $ take (r ^. r_version - p_version) (r ^. r_history)
+        q_table = q ^. _PatchMap . at ngramsType . _Just . _PatchMap . at listId . _Just
+
+      pure (Versioned (r ^. r_version) q_table)
+
+  | otherwise         = do
       let ngramsType        = ngramsTypeFromTabType maybeTabType
           (p0, p0_validity) = PM.singleton listId p_table
           (p, p_validity)   = PM.singleton ngramsType p0