mORMot Open Source

larand54

Member

Registered: 2018-12-25

Posts: 104

Invalid pointer operation when using IList with CreateAndFillPrepare

I get this error when the IList<TOrm> is zero referenced after using CreateAndFillPrepare.

// TOrmArticles is the same as IList<TArticle>
function TDHSSyncRepository.GetAllArticles(var aArts: TOrmArticles):TSyncRepoError;
var
  ormArt: TOrmArticle;
  i: integer;
begin
  result := srNotFound;
  i := 0;
//  result := Collections.NewList<TOrmArticle>; //Tested doing this call outside/inside this function but same result.
  ormArt := TOrmArticle.CreateAndFillPrepare(FRestOrm,'',[]);
  while ormArt.FillOne do begin
    aArts.Add(ormArt);
  end;
  result := srSuccess;
end;

When aArts no longer used  I get the error.
What's wrong here?

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Delphi-11, WIN10

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 14,655

Website

Re: Invalid pointer operation when using IList with CreateAndFillPrepare

FillOne is ... filling one ormArt instance... (as its name states)
So you are adding the very same TOrmArticle  instance several times to the list.
Therefore, when you free the list you free the instance more than once.

So create a new TOrmArticle instance each time, or - even better - use the IList<> generics methods of FRestOrm.

larand54

Member

Registered: 2018-12-25

Posts: 104

Re: Invalid pointer operation when using IList with CreateAndFillPrepare

Beutifull! Thanks!

This is the result:

function TDHSSyncRepository.GetAllArticles(var aArts: TOrmArticles):TSyncRepoError;
var
  ormArt: TOrmArticle;
begin
  result := srNotFound;
  FRestOrm.RetrieveIList(TOrmArticle, aArts);
  if aArts.Count < 1 then
    exit;
  result := srSuccess;
end;

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Delphi-11, WIN10