You probably have some mixed up installation issues.
If you are able to get my latest installer which I put in the evaluation and
registered users areas, running it should wash out whatever problems you are
having.

Please get the latest and let me know.

PS. As of now, I just released IBO 4.5 Ag that is my release candidate 1
build.

Thanks,
Jason Wharton
www.ibobjects.com

> -----Original Message-----
> From: Salvatore Besso [mailto:s.besso@...]
> Sent: Thursday, November 25, 2004 4:10 AM
> To: Lista IB Objects
> Subject: [IBO] Urgent help needed with an access violation
>
>
>
> hello all,
>
> I hope to be in time before Jason releases the next official
> version, but
> suddendly I receive an AV simply trying to open an TIB_Query
> that has a
> perfectly legal SQL statement. But notice that this happens
> only the second time
> that I try to open it.
>
> Very schematic scenario:
>
> - The data module containing the query is created and the
> query is still closed. This DM is used by two forms
> - Creation of a first form that doesn't use that query
> - Creation on demand of a second form that uses that query
> that has an TIB_Grid for browsing and an TIB_LocateEdit
> for searching
>
> The data-module contains two public procedures:
>
> procedure TMyDM.OpenEditTables;
> begin
> EditQuery.Prepare;
> EditQuery.Params.ByName('LOGOWNER').AsInteger := FOwnerID;
> EditQuery.Open;
> ProvQuery.Prepare;
> ProvQuery.Open;
> ModeQuery.Prepare;
> ModeQuery.Open
> end;
>
> procedure TMyDM.CloseEditTables:
> begin
> EditQuery.Close;
> EditQuery.Unprepare;
> ProvQuery.Close;
> ProvQuery.Unprepare;
> ModeQuery.Close;
> ModeQuery.Unprepare
> end;
>
> This is the OnCreate handler for the second form:
>
> begin
> inherited;
> MyDM.OpenEditTables
> end;
>
> and this is the OnClose handler for the second form:
>
> begin
> MyDM.CloseEditTables
> end;
>
> The first time the second form is created all works as
> expected, the queries are
> opened and I can browse the data. Then I close the second
> form that is freed and
> its variable nil'ed and of course the TIB_Query's are closed
> (the data-module
> still exists in memory because is used by the first form as
> well) and I return
> to the first form. Now I open the second form for edit another time:
>
> procedure TMyDM.OpenEditTables;
> begin
> EditQuery.Prepare;
> EditQuery.Params.ByName('LOGOWNER').AsInteger := FOwnerID;
> EditQuery.Open;
> ProvQuery.Prepare;
> ProvQuery.Open; // <--- blam! Access violation
> ModeQuery.Prepare;
> ModeQuery.Open
> end;
>
> I'm still investigating on the possible reasons of this AV
> but I still can't
> figure out why it happens, but it seems that it is something
> related to
> KeyLinks. ProvQuery and ModeQuery have both KeyLinks and
> KeyDescLinks defined
> (only one column) and the KeySource is EditQuery for both. At
> some point in
> IB_Components, in method TIB_Dataset.CheckKeyLinksMaps, the
> KeyLinks columns are
> stored in KeyLinks.Objects and the first time the query is
> opened all is ok. But
> the second time the query is opened, I don't know for what
> reason, an invalid
> pointer is stored in KeyLinks.Objects and then, in method
> TIB_Dataset.SysUpdateKeyLinksData at line 28675 the instruction
> "keyCol.Assign( tmpCol )" causes the AV because tmpCol
> contains the invalid
> pointer (but that is not nil nor equal to Pointer(-1)) retrieved from
> KeyLinks.Objects.
>
> I repeat that this query normally works without problems. The
> problem arises
> only when I open it the second time, and another strange
> thing that doesn't
> always happen is that after the AV sometimes the query is in
> edit mode instead
> of browse mode. To make things work again I have to close the
> first form,
> destroy the data-module and repeat the process again
> (data-module creation,
> first form creation and second form creation). I have also
> tried to remove all
> event handlers from the query and its datasource, but without
> success, the AV
> still happens.
>
> So far, so bad :-( I continue investigation but a help or an
> indication from you
> would be greatly appreciated.
>
> Regards
> Salvatore
>