C++ Builder 64-Bit only: TVirtualStringTree->Header: SortColumn and SortDirection give always the same return value

[Dirk-Ahnenblatt]

Very strange behaviour in 64-Bit versions of C++ Builder projects (RAD Studio 12.3 with Virtual-TreeView-8.2) ...

I can set TVirtualStringTree->Header->SortColumn with a new value, that's Ok. But getting the value returns always 8 (even when getting the value directly after setting a new one!). As I found out, the return value is always the value of TVirtualStringTree->Header->SplitterHitTolerance (when changing SplitterHitTolerance value, the return value of SortColumn changes!).

Same problem with TVirtualStringTree->Header->SortDirection which also returns always the same value.

While 32-Bit version works fine, it is an unexpected behaviour in both 64-Bit versions (modern or not).
Delphi projects (32-/64-Bit) are not affected.

After replacing property read variables by functions everything works as expected.

Could be a bug in 64-bit-compilers - perhaps fixed in RAD Studio 13 (I have not updated yet). More properties could be affected in the same way.

Here are the lines I have changed (in TVTHeader class):

    property SortColumn           : TColumnIndex read GetSortColumn write SetSortColumn default NoColumn;
    property SortDirection        : TSortDirection read GetSortDirection write SetSortDirection default sdAscending;

function TVTHeader.GetSortColumn : TColumnIndex;
begin
  if FColumns.Count > 0 then
    Result := FSortColumn
  else
    Result := NoColumn;
end;

function TVTHeader.GetSortDirection : TSortDirection;
begin
  Result := FSortDirection
end;

[joachimmarder]

I don't use C++ Builder, but so far we did not receive any similar reports.

Did you recently upgrade from an older version of Virtual TreeView? If so, which version was this?

You could play around with the order of the members of TVTHeader or with the type of the property (Int32, Int64, Integer) to narrow down the problem or to prove that this is a compiler bug.

[Dirk-Ahnenblatt]

Did you recently upgrade from an older version of Virtual TreeView? If so, which version was this?

Yes. New version is Virtual-TreeView-8.2 - as I wrote in my first posting. Seems to be the newest version.

You could play around with the order of the members of TVTHeader or with the type of the property (Int32, Int64, Integer) to narrow down the problem or to prove that this is a compiler bug.

I found a solution in my case by changing some lines of code (see first posting). You can add them to the source code or I do it only for me, when I update Virtual TreeView.

From my point of view it is a compiler bug and I just wanted to report the unusual behavior and a workaround. To report a compiler bug to Embarcadero, you would have to simplify the source code a lot - instead of referring to the complete github code here. I don't have the time at the moment ...