Shadowed properties cause errors during FieldDef initialization

[Zane Duffield]

If a child class publishes a property with the same name as a parent class, TObjectDataSet will attempt to add multiple fields with the same name, which leads to an error.

It feels most appropriate to me for the property from the child class to be used. This can be achieved by only including the first property for a given name when enumerating the properties in InitRttiPropertiesFromItemType (thereby excluding the duplicates from fProperties) or by doing a similar thing inside InitRttiPropertiesFromItemType where the TFieldDefs are added.

[Stefan Glienke]

Isn’t that also already fixed in 2.0? Please retest

[Zane Duffield]

I don’t think it’s fixed in the latest develop branch.

Here’s a minimal reproducible case for this issue which should work on both master and develop.

program ShadowedPropertyBug;

uses
  Spring.Data.ObjectDataSet, Spring.Collections;

type
  TFoo = class(TObject)
    private
      FBar: Integer;
    published
      property Bar: Integer read FBar write FBar;
  end;

  TBar = class(TFoo)
    published
      property Bar: Integer read FBar write FBar;
  end;

var
  ods: TObjectDataSet;
begin
  ods := TObjectDataSet.Create(nil);
  ods.datalist := TCollections.CreateObjectList<TBar> as IObjectList;
  // error on open: Duplicate name 'Bar' in TFieldDefs
  ods.open;
end.

It might be useful to add a note to the ‘Know Issues’ section of the README in the master branch that mentions that the latest bug fixes are only found in the develop branch.
I didn’t think to use anything but master when starting out with Spring4D.

[Stefan Glienke]

fixed #390

→ <<cset dc0bc32a013c>>