ModelCompiler generates Variables with duplicate NodeIds

[bengeisler]

The ModelCompiler generates NodeSet2.xml files with duplicate NodeIds in some cases. I'll describe a minimal example that reproduces this:

Let's say I have some DataType FooStruct which is a Structure:

    <UADataType NodeId="ns=1;i=3000" BrowseName="1:FooStruct">
        <DisplayName>FooStruct</DisplayName>
        <References>
            <Reference ReferenceType="HasSubtype" IsForward="false">i=22</Reference>
            <Reference ReferenceType="HasEncoding">ns=1;i=5001</Reference>
            <Reference ReferenceType="HasEncoding">ns=1;i=5002</Reference>
        </References>
        <Definition Name="1:FooStruct">
            <Field DataType="Boolean" Name="FooItem"/>
        </Definition>
    </UADataType>

It has just one field, namely FooItem of type Boolean.

Now, I'll derive a VariableType from this:

    <UAVariableType DataType="ns=1;i=3000" NodeId="ns=1;i=2000" BrowseName="1:FooVariableType">
        <DisplayName>FooVariableType</DisplayName>
        <References>
            <Reference ReferenceType="HasSubtype" IsForward="false">i=63</Reference>
            <Reference ReferenceType="HasComponent">ns=1;i=6015</Reference>
        </References>
    </UAVariableType>

This gives me a InstanceDeclaration of FooItem, the field of the struct just created:

    <UAVariable DataType="Boolean" NodeId="ns=1;i=6015" BrowseName="1:FooItem" ParentNodeId="ns=1;i=2000" UserAccessLevel="3" AccessLevel="3">
        <DisplayName>FooItem</DisplayName>
        <References>
            <Reference ReferenceType="HasTypeDefinition">i=63</Reference>
            <Reference ReferenceType="HasModellingRule">i=78</Reference>
        </References>
    </UAVariable>

Now I go on to create an ObjectType:

    <UAObjectType NodeId="ns=1;i=1000" BrowseName="1:FooObjectType">
        <DisplayName>FooObjectType</DisplayName>
        <References>
            <Reference ReferenceType="HasSubtype" IsForward="false">i=58</Reference>
            <Reference ReferenceType="HasComponent">ns=1;i=6016</Reference>
        </References>
    </UAObjectType>

that has one child:

    <UAVariable DataType="ns=1;i=3000" NodeId="ns=1;i=6016" BrowseName="1:Foo" ParentNodeId="ns=1;i=1000" UserAccessLevel="3" AccessLevel="3">
        <DisplayName>Foo</DisplayName>
        <References>
            <Reference ReferenceType="HasTypeDefinition">ns=1;i=2000</Reference>
            <Reference ReferenceType="HasModellingRule">i=78</Reference>
            <Reference ReferenceType="HasComponent">ns=1;i=6015</Reference>
        </References>
    </UAVariable>

which has a HasTypeDefinition reference that points to the previously created VariableType FooVariableType.

Now comes the issue: when running this file through the ModelCompiler:

docker run \
-v $(pwd):/nodesets \
--rm ghcr.io/opcfoundation/ua-modelcompiler:latest compile \
-d2 /nodesets/model/foo.xml,foo.com \
-d2 /nodesets/schema/ua/Opc.Ua.NodeSet2.xml,Opc.Ua \
-o2 generated/foo

this generates two Variable nodes with the same NodeId:

  <UAVariable NodeId="ns=1;i=6015" BrowseName="1:FooItem" ParentNodeId="ns=1;i=2000" DataType="Boolean" AccessLevel="3">
    <DisplayName>FooItem</DisplayName>
    <References>
      <Reference ReferenceType="HasTypeDefinition">i=63</Reference>
      <Reference ReferenceType="HasModellingRule">i=78</Reference>
      <Reference ReferenceType="HasComponent" IsForward="false">ns=1;i=2000</Reference>
    </References>
  </UAVariable>
  <UAVariable NodeId="ns=1;i=6015" BrowseName="1:FooItem" ParentNodeId="ns=1;i=6016" DataType="Boolean" AccessLevel="3">
    <DisplayName>FooItem</DisplayName>
    <References>
      <Reference ReferenceType="HasTypeDefinition">i=63</Reference>
      <Reference ReferenceType="HasModellingRule">i=78</Reference>
      <Reference ReferenceType="HasComponent" IsForward="false">ns=1;i=6016</Reference>
    </References>
  </UAVariable>

In my opinion, the ModelCompiler should never create a Node with the same id multiple times.
In this specific case it should only generate the first node with the ParentNodeId ns=1;i=2000
In any case, if it were to create the same NodeId again, it should abort the process with an error message.

Attached two files:
foo.xml is the input provided to the ModelCompiler
foo.com.NodeSet2.xml is the generated output