Article ID: 158707
Article Last Modified on 11/1/2006
APPLIES TO
- Microsoft Windows NT Workstation 4.0 Developer Edition
- Microsoft Windows NT Server 4.0 Standard Edition
This article was previously published under Q158707
SYMPTOMS
Code that tries to destroy a DDEML window under Windows NT 4.0 can result in an access violation (AV), while the same code running on Windows NT 3.51 will have no problems.
Under Windows NT 4.0, the access violation results in the following message:
NOTE: The second, third, and fourth parameter may vary from system to system.
CAUSE
This problem was discovered when using a third party application that uses DDEML to communicate between the main application and a plug-in application. The DDEML window is destroyed after communication is completed. In the window destroy process, Windows NT code intercedes and cleans up DDEML-related resources, and then continues on with the generic window destroy. During this cleanup process under Windows NT 4.0, a null member eventually will be introduced that will result in an AV. This problem does not occur under Windows NT 3.51, because the code has moved to the kernel under Windows NT 4.0.
RESOLUTION
This problem was resolved by adding code to the FreeDdeConv to account for critical section exit when the DDEML struct is vulernable to the client side.
STATUS
Microsoft has confirmed this to be a problem in Windows NT version 4.0. This problem was corrected in the latest Microsoft Windows NT 4.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):
S E R V P A C K
Additional query words: prodnt 0x1e
Keywords: kb3rdparty kbprogramming KB158707
