[fpc-pascal] assigning ansistring with shortstring

[L505]

> > I'm lacking some memory concept here. Below program doesn't work
> > unless setlengths
> > are called first on the shortstrings.
> >
> > program Project1;
> >
> > {$mode objfpc}{$H+}
> >
> > var
> >   filename: string;
> >   last3: string[3];
> >   last4: string[4];
> > begin
> >   filename:= 'test';
> >   filename:= filename+ 'ing.pas';
> >   setlength(last3, 3);
> >   last3[1]:= filename[length(filename)-2];
> >   last3[2]:= filename[length(filename)-1];
> >   last3[3]:= filename[length(filename)];
> >   writeln('debug last3: ' + last3);
>
> The length bytes of those shortstrings aren't initialised if you
> don't do setlength(). It has nothing to do with memory allocation,
> but with initialisation.
>

Learn something new today - I unfortunately don't have a turbopascal background and in
this case it would really help - I guess I made the silly assumption that shortstrings
were ready to go without ever needed a setlength. Of course I had the nerve to turn off
range checking and try accessing outside of 255 bounds but it didn't work, as expected :-)