A problem with comctl32

Rolf Kalbermatter r.kalbermatter at hccnet.nl
Sun Nov 3 15:11:52 CST 2002

DanteAliegri <dantealiegri at umbc.edu> wrote:

>Hey, I've come across what appears to be a
>simple problem in comctl32.
>When running icq99b, wine was dying in imagelist.c while trying to 
>dereference a null pointer.
>Upon looking at the file,  there was code for returning FALSE if that 
>pointer was null, thus I felt it being null may be a valid choice.
>I made the attached change, and the problem was fixed.
>--- imagelist.c	23 Oct 2002 22:19:11 -0000	1.65
>+++ imagelist.c	2 Nov 2002 20:40:53 -0000
>@@ -1082,11 +1082,14 @@
>     HBITMAP hImageBmp, hOldImageBmp, hOldImageListBmp, hOldMaskListBmp,
>     BOOL bIsTransparent, bBlend, bResult = FALSE;
>     const HIMAGELIST himl = pimldp->himl;
According to the same lines pimldp could also be NULL so this might as
well cause a NULL pointer dereference and should be moved to after the
check for "if (!pimldp || !(himl = pimldp->himl)) return FALSE;

Of course the question remains why would you call the function at all
with a NULL pointer.

>-    const INT lx = himl->cx * pimldp->i + pimldp->xBitmap;
>-    const INT ly = pimldp->yBitmap;
>+    static INT lx;
>+    static INT ly;

Should this be really static? Can't this function be called reentrant?

>     if (!pimldp || !himl) return FALSE;
>     if ((pimldp->i < 0) || (pimldp->i >= himl->cCurImage)) return FALSE;
>+		lx = himl->cx * pimldp->i + pimldp->xBitmap;
>+		ly = pimldp->yBitmap;

Rolf Kalbermatter

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