[DUG] EAccessViolation on StdWndProc

[Leigh Wanstead]

Hello everyone,

I got EAccessViolation on StdWndProc on customer machine

The development environment is Delphi 7 Enterprise. The customer's os are
Windows 2003 and xp.

Exception Message is:

Access violation at address 00000000 Write of address 00000000

The whole call stack from EurekaLog v 5.x log is

classes.pas StdWndProc
user32.dll DispatchMessageA
user32.dll DispatchMessageA
Forms.pas TApplication.ProcessMessage
Forms.pas TApplication.ProcessMessage
Forms.pas TApplication.HandleMessage
Forms.pas TApplication.HandleMessage
Forms.pas TApplication.Run
Forms.pas TApplication.Run
MyProject.dpr

function StdWndProc(Window: HWND; Message, WParam: Longint;
  LParam: Longint): Longint; stdcall; assembler;
asm
        XOR     EAX,EAX
        PUSH    EAX
        PUSH    LParam
        PUSH    WParam
        PUSH    Message
        MOV     EDX,ESP
        MOV     EAX,[ECX].Longint[4]
-->        CALL    [ECX].Pointer
        ADD     ESP,12
        POP     EAX
end;

I can not duplicate the error on my own machine on xp and windows 2000
terminal server. It happens random on customer machine. May I ask how to do
in code to catch the error?

TIA

Regards
Leigh