Fix crash NRE executing query for aggregator connection. Closes #197

Author: kaidaguerre

hub/connection_map.go

@@ -50,6 +50,7 @@ func (f *connectionFactory) get(pluginFQN, connectionName string) (*steampipecon
 	// if this is an aggregate connection, return error
 	// (we must iterate through the child connections explicitly)
 	if f.hub.IsAggregatorConnection(connectionName) {
+		log.Printf("[WARN] connectionFactory get %s %s called for aggregator connection - invalid (we must iterate through the child connections explicitly)", pluginFQN, connectionName)
 		debug.PrintStack()
 		return nil, fmt.Errorf("the connectionFactory cannot return or create a connectionPlugin for an aggregate connection")
 	}

hub/hub.go

@@ -193,6 +193,14 @@ func (h *Hub) AddScanMetadata(iter Iterator) {
 	}
 	ctx := iter.GetTraceContext().Ctx
 
+	// if this is a group iterator, recurse into AddScanMetadata for each underlyinh iterator
+	if g, ok := iter.(*groupIterator); ok {
+		for _, i := range g.Iterators {
+			h.AddScanMetadata(i)
+			return
+		}
+	}
+
 	connectionName := iter.ConnectionName()
 	connectionPlugin, _ := h.getConnectionPlugin(connectionName)
 
@@ -438,7 +446,7 @@ func (h *Hub) GetPathKeys(opts types.Options) ([]types.PathKey, error) {
 	//}
 	//pathKeys := types.MergePathKeys(getCallPathKeys, listCallPathKeys)
 
-	log.Printf("[TRACE] GetPathKeys for connection '%s`, table `%s` returning \n%v", connectionName, table, pathKeys)
+	log.Printf("[TRACE] GetPathKeys for connection '%s`, table `%s` returning", connectionName, table)
 	return pathKeys, nil
 }