[fpc-pascal] Regression? Problem passing a packed record to a overriden, virtual, abstract method in fpc 2.7.1.

[Mattias Gaertner]

On Sun, 24 Feb 2013 23:20:23 +0100
Reimar Grabowski <reimgrab at web.de> wrote:

> Hi,
> 
> see the following little program:
> 
> program argumentbug;
> 
> {$MODE ObjFpc}
> 
> uses classes;
> 
> type
> 
> TVector3 = packed record
>   X, Y, Z: Single;
> end;
> 
> TClassA = class
> protected
>   fVector: TVector3;
> public
>   procedure SetVector(AVector: TVector3); virtual; abstract;
> end;
> 
> { TClassB }
> 
> TClassB = class(TClassA)
> public
>   procedure SetVector(AVector: TVector3); override;
> end;
> 
> { TClassB }
> 
> procedure TClassB.SetVector(AVector: TVector3);
> begin
>   writeln('TClassB: ',AVector.X,',',AVector.Y,',',AVector.Z);
>   fVector:=AVector;
> end;
> 
> var
>   MyVector: TVector3;
>   MyClassB: TClassB;
> begin
>   MyVector.X:=0;
>   MyVector.Y:=0;
>   MyVector.Z:=3;
>   MyClassB:=TClassB.Create;
>   MyClassB.SetVector(MyVector);
> end.
> 
> Obviously the expected output is 0,0,3 but in fact the output is 0,3,3.
> I am sure that this used to work as my real code showing the problem is many years old.
> (The problem stays even if I don't declare the method in TClassA abstract.)
> 
> OS: Ubuntu 12.10 64-Bit
> Compiler: FPC 2.7.1 Rev. 23655

It works under 2.6.0 and 2.6.2 (Ubuntu 64bit).

Mattias