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Q221679: FIX: Servers Do Not Release if Init Returns .F.

Article: Q221679
Product(s): Microsoft FoxPro
Version(s): 6.0
Operating System(s): 
Keyword(s): kbservicepack kbCOMt kbOOP kbvfp600 kbvfp600bug kbVS600sp2 kbVS600SP1 kbVS600sp3fix kbG
Last Modified: 26-OCT-2000

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

- Microsoft Visual FoxPro for Windows, version 6.0 
-------------------------------------------------------------------------------

SYMPTOMS
========

The following errors are received when you try to load a Visual FoxPro COM DLL
or COM EXE.

In Visual FoxPro, the error is:

  OLE error code 0x80004005: Unspecified error.

When using Visual Basic or Visual Basic for Applications in Excel 97, the error
is:

  Run-time error '-2147467259(80004005)':
  Automation error
  Unspecified error

After the error, the COM server cannot be rebuilt or deleted. If a Visual FoxPro
COM EXE is called, it does not show in the Windows NT Task Manager in the
Processes tab. A COM DLL does not show up in the Task Manager as it loads
In-Process by definition. However, the COM DLL cannot be deleted. In Windows 95
or Windows 98, the Close Program window shows the Visual FoxPro COM EXE.

In other words, the Visual FoxPro COM server remains in memory.

CAUSE
=====

This is known to happen if the Visual FoxPro COM server's Init method returns
False (.F.).

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information
about Visual Studio service packs, please see the following articles in the
Microsoft Knowledge Base:

Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

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

This article helps you attempt to delete the Visual FoxPro COM DLL to test to
see if there is a sharing violation. If there is, this is an indication that the
COM DLL is loaded in memory.

Note that if you attempt to load COM DLL in Visual Basic 6.0, you can delete
Visual FoxPro COM DLL. This is different than attempting to load Visual FoxPro
COM DLL into Excel 97 VBA. In Excel 97 VBA, you cannot delete the COM DLL until
Excel is closed. However, attempting to load a Visual FoxPro COM EXE in Visual
Basic 6.0 leaves the VFP COM EXE running.

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

1. Place the following code into a new program file and save it as
  falseinit.prg:

     DEFINE CLASS falseinit AS custom OLEPUBLIC

          Name = "falseinit"

          PROCEDURE Init
             RETURN .F.
          ENDPROC

          PROCEDURE hello
             RETURN "Hello There"
          ENDPROC

          PROCEDURE ERROR()
             LPARAMETERS nError, cMethod, nLine
             errStr="ErrorNum: " + STR(nError) + ;
               "Method Name: " + cMethod + ;
               "On Line: " + STR(nLine) + ;
               "Message: " + MESSAGE()

             STRTOFILE(errStr,"c:\falseinit.txt",.T.)
             COMRETURNERROR(cMethod,errStr)
          ENDPROC

     ENDDEFINE

2. Add the program to a new project named falseinit.prg and build the project
  into a Visual FoxPro EXE.

3. Issue the following commands in the Visual FoxPro Command window to attempt
  to load the COM EXE and check the variable type:

  ox=CreateObject("falseinit.falseinit")
  ? VARTYPE(ox)

4. Press the ENTER key to run the first line of code above, and note that the
  "OLE error code 0x80004005: Unspecified error" is received. The VARTYPE()
  function should return "U," indicating that the ox variable does not contain
  an object reference.

5. Bring up the Windows NT Task Manager and go to the Processes tab.
  Falseinit.exe should be listed. End Process on it to unload the VFP COM EXE
  from memory.

6. The following code can be used in Visual Basic or Excel 97 Visual Basic for
  Applications to load the Visual FoxPro COM EXE built previously. It assumes
  that you have a working knowledge of Visual Basic or Visual Basic for
  Applications.

  Sub VFPTest()

  Dim ox As Object
  Set ox = CreateObject("falseinit.falseinit")
  Set ox = Nothing

  End Sub

Note that there is an Error() method in the code for the VFP COM server. This
code should write a file named "falseinit.txt" to the root of the C: drive and
also should return information about the error. A search of the C: drive after
trying to load the falseinit.exe unsuccessfully does not turn up the
falseinit.txt file. This occurs because the Error() method is never run; the
Init() method returns False and the COM server does not fully instantiate. This
is the bug.

Additional query words:

======================================================================
Keywords          : kbservicepack kbCOMt kbOOP kbvfp600 kbvfp600bug kbVS600sp2 kbVS600SP1 kbVS600sp3fix kbGrpDSFox 
Technology        : kbVFPsearch kbAudDeveloper kbVFP600
Version           : :6.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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