BUG: ASSERT in WinOcc.cpp when Hosting a WebBrowser Control in an MFC Container

• The Microsoft Foundation Classes (MFC), included with:
  • Microsoft Visual C++, 32-bit Enterprise Edition, versions 5.0, 6.0

SYMPTOMS

Take a CHtmlView based application or have a dialog hosting a web browser control. Go to a local folder. Right-click and select either New Folder or one of the file types listed there. It will ASSERT in WinOcc.cpp, Line 331. This does not have any impact on the release build.

CAUSE

This is due to a bug in MFC for UI activation of an ActiveX control.

RESOLUTION

Override the PreTranslateMessage function in the dialog class or the one derived from CHtmlView. If the message is WM_RBUTTONDOWN, return 0. The code should look like this:

BOOL CMyDialog::PreTranslateMessage(MSG* pMsg) 
{
	if (pMsg->message == WM_RBUTTONDOWN)
		return 0;

	return CDialog::PreTranslateMessage(pMsg);
} 

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. Generate an AppWizard application and select CHtmlView class as the base class of your view class in Step 6 of the AppWizard.



2. Provide a valid path to one of the local folders. Modify the OnInitialUpdate of the view class as shown below:
   
   

   
   void CMyHTMLView::OnInitialUpdate()
   {
   	CHtmlView::OnInitialUpdate();
   
   	Navigate2(_T("C:\\Temp"),NULL,NULL);
   } 




3. Build the EXE and run it.



4. Right-click inside the view and select New Folder.

Additional query words: CHtmlView

Keywords : kbActiveX kbContainer kbCtrl kbMFC kbWebBrowser
Version : winnt:
Platform : winnt
Issue type : kbbug