How to free TOleStream in this bit of code

Question

This is from a custom namespacer handler done in Delphi I use to load files into a webbrowser component.

Datastream:IStream;

var
  F: TFileStream;
  Dummy: INT64;
begin

  F:=TFileStream.Create(strfilename fmOpenRead);
  CreateStreamOnHGlobal(0, True, DataStream);
  TOleStream.Create(DataStream).CopyFrom(F, F.Size);
  DataStream.Seek(0, STREAM_SEEK_SET, Dummy);
  TotalSize := F.Size;
  F.Free;
end;

The problem is that Fastmm4 gives a memory leak error when the program ends and says that TOleStream was not freed. How do I free it? If I put TOleStream in a variable and assign like this

var
TOS:TOleStream;

TOS:=TOleStream.Create(DataStream)
TOS.CopyFrom(F, F.Size);

..
TOS.Free;
End;

I get an error (EAccessViolation pointing to TComObject.ObjRelease in ComObj)in the end when I free the TOS variable. I would appreciate your comments and help. This problem has been bugging me for a while now.

I am also wondering if it could be something with FastMM4? Could it be giving false information? In a bit of code like the following. How is TOLEStream freed typically?

f.SaveToStream(TOleStream.Create(DataStream));

And is there a way to send data to datastream without using the TFileStream?

Hi Remy, You can find a working demo project of the namespace handler with the fastmm and the problem procedure here: http://mode5.webs.com/namespace.7z When the project loads, click the button to have the namespace handler load the files. When you exit, you should get the fastmm error. Kind regards,

Answer 1

If you need to pass an IStream interface to something, you should look into the TStreamAdapter object, you can create one on the TFileStream, and pass its IStream interface.