DOCUMENT:Q190492  07-AUG-1998  [vbwin]
TITLE   :BUG: New Implements Does Not Generate Incompatibility Error
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:
OPER/SYS:WINDOWS
KEYWORDS:

======================================================================
---------------------------------------------------------------------
The information in this article applies to:

 - Microsoft Visual Basic Learning, Professional, and Enterprise Editions
   for Windows, version 6.0
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SYMPTOMS
========

If you remove a Public data member and add an Implements statement with the
same class name as the removed Public data member and with Binary
Compatibility set, Visual Basic does not generate a compatibility error as
expected.

Existing client applications using the data member may generate a fatal
error (GPF) with the new compatible server.

RESOLUTION
==========

If you comment out Public data members, ensure you are not using the same
identifier name in an Implements statement.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed
at the beginning of this article. We are researching this bug and will post
new information here in the Microsoft Knowledge Base as it becomes
available.

MORE INFORMATION
================

Steps to Reproduce Behavior
---------------------------

1. Create a new ActiveX DLL project in Visual Basic. Class1 will be created
   by default.

2. Set the Instancing Property of Class1 to 2-PublicNotCreateable.

3. Add a Class to the project by selecting Add Class Module from the
   Project menu.

4. Add the following code to Class1:

      Public Class2 As Class2

5. Add the following code to Class2:

      Public Class1 As Class1

6. From the File Menu, click on Make Project1 to compile the Project and
   make Project1.dll

7. From the Project Menu, select Project1 Properties.

8. Select the Component tab, check the Binary Compatibility Radio
   Button, and then click OK to set Binary Compatibility.

9. Comment out the data member in Class2 as shown below:

      ' Public Class1 As Class1

10. In Class2, paste the following code:

      Implements Class1
      Private Property Set Class1_Class2(ByVal RHS As Class2)

      End Property

      Private Property Get Class1_Class2() As Class2

      End Property

11. Recompile the project, and make the Project1.Dll. Note that the ActiveX
DLL compiles as expected. However, a compatibility error should have
    been raised.

Additional query words: kbdss kbDSupport kbVBp kbVBp600bug kbCompiler
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Platform          : WINDOWS
Issue type        : kbbug

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