Question

following code triggers an EIntOverflow exception.
I can not debug it because that happens on a user PC, not mine.

var

  dwread, iBytesPerMFTRecord : cardinal;

  pc : PChar;

begin

////
// some code here
////

Readfile(hDevice, PChar(pc)^, 100, dwread, nil);


for n:=0 to dwread div iBytesPerMFTRecord -1 do   // `EIntOverflow` exception

It seems that Readfile is returning something strange for dwread which triggers an
EIntOverflow exception on following line.

1°) What could be returned for dwread to trigger this exception ?

2°) How to control that ?

Answer 1

Zero I guess:

{$Q+}
procedure TForm1.Button2Click(Sender: TObject);
var
  dw: Cardinal;
  I: Integer;

begin
  dw:= 0;
  I:= dw - 1;   // raised exception class EIntOverflow with message 'Integer overflow'.
  ShowMessage(IntToStr(I));
end;