[NF] Fix checkConnectorType for derived nodes.

Belonging to [master]:
  - #2933

Author: perost

3rdParty

@@ -95,6 +95,12 @@ algorithm
       case ConnectorType.POTENTIAL then potfunc(set);
       case ConnectorType.FLOW then generateFlowEquations(set);
       case ConnectorType.STREAM then generateStreamEquations(set, flowThreshold);
+      else
+        algorithm
+          Error.addInternalError("Invalid connector type on set "
+            + List.toString(set, Connector.toString, "", "{", ", ", "}", true), sourceInfo());
+        then
+          fail();
     end match;
 
     equations := listAppend(set_eql, equations);

Compiler/NFFrontEnd/NFConnectEquations.mo

@@ -457,12 +457,14 @@ end checkComponentAttributes;
 function checkConnectorType
   input InstNode node;
   output Boolean isConnector;
+protected
+  InstNode dnode = InstNode.getDerivedNode(node);
 algorithm
-  if InstNode.isEmpty(node) or InstNode.isInnerOuterNode(node) then
+  if InstNode.isEmpty(dnode) or InstNode.isInnerOuterNode(dnode) then
     isConnector := false;
   else
-    isConnector := Class.isConnectorClass(InstNode.getClass(node)) or
-                   checkConnectorType(InstNode.parent(node));
+    isConnector := Class.isConnectorClass(InstNode.getClass(dnode)) or
+                   checkConnectorType(InstNode.parent(dnode));
   end if;
 end checkConnectorType;