FIX: Memory Leak With SET SYSMENU OFF (221738)

SYMPTOMS

If you repeatedly run a form and the system menu is set off, the following error may eventually occur:

There is not enough memory to complete this operation.

After that message appears, Visual FoxPro may have difficulty performing other tasks and report more insufficient memory messages.

STATUS

Microsoft has confirmed that this is a bug in the Microsoft products that are 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:

194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

MORE INFORMATION

Steps to Reproduce Behavior

Run the following code from a program (.prg) file:

   CLEAR ALL
   PUBLIC Pubrunform
   Pubrunform=.T.
   SET SYSMENU OFF

   ON KEY LABEL ctrl+f8 _SCREEN.FORMS(1).RELEASE()
   ON ESCAPE Pubrunform=.F.
   X=1
   DO WHILE Pubrunform=.T.
	WAIT '' TIME .08 && take this out and get ox or forms
   && is not an object
	ox=CREATEOBJECT('form')
	ox.CAPTION = ALLTRIM(STR(X)) +' iterations - press escape to quit'
	KEYBOARD '{ctrl+f8}'
	ox.SHOW(1)
	X=X+1
   ENDDO
   ON KEY LABEL ctrl+f8
   SET SYSMENU TO DEFAULT
   SET SYSMENU AUTO
   ON ESCAPE
   RETURN

NOTE: If you get either of these messages press Ignore:
ox is not an object.

-or-
forms is not an object.

Eventually, you get the following error:

There is not enough memory to complete this operation.

The error usually occurs after about 500 iterations. The same behavior happens in Visual FoxPro 5.0a and 6.0.

If you look at the VFP6.exe file in the Windows NT 4.0 Task Manager, you will see the memory usage increase. However, two Visual FoxPro SYS() functions that look at memory usage, SYS(1016) and SYS(1011), do not increase. The error does not occur without the SET SYSMENU OFF command.