DOCUMENT:Q193036  24-SEP-1998  [vbwin]
TITLE   :BUG: "On Error Resume Next" Enters Infinite Loop in Native Code
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:5.0,6.0
OPER/SYS:WINDOWS
KEYWORDS:

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

 - Microsoft Visual Basic Learning, Professional, and Enterprise Editions
   for Windows, versions 5.0, 6.0
---------------------------------------------------------------------

SYMPTOMS
========

After compiling to native code, a Visual Basic application using "On Error
Resume Next" together with a For loop may sometimes enter an infinite loop
when running as a standalone executable.

RESOLUTION
==========

To work around this behavior, the code can be restructured. The code
provided below resolves the problem for the code that reproduces this bug
in the "Steps To Reproduce Behavior" section of this article:

   Public Sub Form_Load()
      On Error Resume Next
      Dim x As Integer
      Dim z as integer
      Dim mArray as Variant
      z = UBound(mArray)
         For x = 0 To z
            MsgBox "clear"
         Next x
   End Sub

STATUS
======

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

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

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

1. Create a standard EXE project in Visual Basic. Form1 is created by
   default.

2. Paste the following code into Form1:

      Public Sub Form_Load()
         On Error Resume Next
         Dim x As Integer
         Dim mArray as Variant
         For x = 0 To UBound(mArray)
            MsgBox "Test"
         Next x
      End Sub

3. Select Properties from the Project menu. Under the Compile tab, select
   Compile to Native Code

4. Run the project by pressing the F5 key. Note that the message box
   displays only once.

5. Select Make Project1.exe to compile the project.

6. Run the compiled executable.

   Instead of displaying one message box, an endless number message boxes
   are displayed.

   On Windows NT, you can terminate this application through the Task
   Manager using the End Task button.
   
   On Win95/98, press the CTRL+ALT+DEL key combination and select the
   program. Press the End Task button to close the application.

Additional query words: kbdss kbDSupport kbVBp kbVBp600bug kbVBp500bug
kbCompiler
======================================================================
Version           : WINDOWS:5.0,6.0
Platform          : WINDOWS
Issue type        : kbbug

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

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 1998.