[fpc-pascal] a queried interface destroyed after writeln the address of it

[ZAN DoYe]

I don't know if it's an undefined behavior or a bug.
The environment is fpc 2.6-bugfix branch x86-64 linux.
See the details in the attached code

program t2;
{$mode objfpc}
    uses sysUtils;
    type
        ip= interface ['{f0cea771-a3f1-4223-bea2-c46c5f0f61fa}']
        end;
        iq= interface ['{11d7c834-7fcf-4837-bccc-fa92418a049b}']
        end;

        cl= class(tInterfacedObject, ip, iq)
            public
                destructor destroy; override;
        end;
            destructor cl.destroy;
            begin
                writeln('cl destroyed');
            end;

    type
        cm= class(tInterfacedObject, ip, iq)
            public
                fi: cl;
                property i0: cl read fi implements ip;
                property i1: cl read fi implements iq;
                constructor create; virtual;
                destructor destroy; override;
        end;
            constructor cm.create;
            begin
                fi:= cl.create;
            end;
            destructor cm.destroy;
            begin
                freeAndNil(fi);
            end;

    var v: cm;
        i: ip;
begin
    v:= cm.create;
    writeln(ptruint(v));
    writeln(ptruint(v as ip));
        // it prints 'cl destroyed'
    // i:= v; // if uncommented this line, no exception would be raised. But in delphi, the next statement works well even leave it commented.
    writeln(ptruint(v as iq));
        // EAccessViolation : Access violation
end.


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