Exception in DefWindowProcA

[Paul Vriens]

Hi,

when running proces explorer (V9.0.3) and some hacks, I get an exception
in DefWindowProcA:

trace:message:SPY_EnterMessage         (0x20022)  DefWindowProc32:
WM_GETTEXT [000d]  wp=00000100 lp=00000000

Call kernel32.WideCharToMultiByte(00000000,00000000,6b2592e0 L"Process
Explorer - Sysinternals:
www.sysinternals.com",ffffffff,00000000,00000100,00000000,00000000)
ret=61b8be5
Ret  kernel32.WideCharToMultiByte() retval=00000000 ret=61b8be52

trace:seh:EXC_RtlRaiseException code=c0000005 flags=0 addr=0x61b8be5c

It somewhat boils down to this piece of code in defwnd.c:

line:754
if (wndPtr->text)
{
    if (!WideCharToMultiByte( CP_ACP, 0, wndPtr->text, -1,
                             dest, wParam, NULL, NULL )) dest[wParam-1] = 0;
    result = strlen( dest );
}
else dest[0] = '\0';
WIN_ReleasePtr( wndPtr );

dest = NULL in my case so I added some tests for this:

if (wndPtr->text)
{
    if (!WideCharToMultiByte( CP_ACP, 0, wndPtr->text, -1,
                             dest, wParam, NULL, NULL ))
    {
        if (dest) dest[wParam-1] = 0;
    }

if (dest) result = strlen( dest );
    else result = 0;
}

This makes the GUI appear but I want to find out if the call is valid or
that we indeed should check for dest being NULL.

Any ideas?

Cheers,

Paul.