[fpc-pascal] Why in {$mode delphi} it works and in {$mode objfpc} it doesn't?

[Michael Van Canneyt]

On Mon, 16 Jan 2023, Giuliano Colla via fpc-pascal wrote:

> I stumbled into a problem I don't understand.
>
> I'm developing a little program for an ftp client. In order to connect to the 
> site I need the site address from the site name, and the libc gethostbyname() 
> provides the required information.
>
> gethostbyname returns a PHostEnt type which is declared as:
>
>> THostEnt = packed record
>>     h_name: PChar;                  { Official name of host. }
>>     h_aliases: PPChar;              { Alias list.  }
>>     h_addrtype: Integer;            { Host address type.  }
>>     h_length: socklen_t;            { Length of address.  }
>>     case Byte of
>>       0: (h_addr_list: PPChar);     { List of addresses from name server.  
>> }
>>       1: (h_addr: PPChar);          { Address, for backward compatibility.  
>> }
>>   end;
>>   PHostEnt = ^THostEnt; 
> Actually the chars h_addr points to are /hlength/ bytes to be interpreted as 
> an /in_addr/
>
> In order to recover h_addr I have a line which works perfectly in Delphi mode 
> (inherited from an old Kylix app):
>
>> Addr := Pin_addr(HostEnt.h_addr^);
> I believed that in objfpc mode it was sufficient to change it in
>
>> Addr := @(Pin_addr(HostEnt.h_addr^));
> or in
>
>> Addr := Pin_addr(@HostEnt.h_addr^);

Should that not simply be

Addr := Pin_addr(HostEnt.h_addr^)

(if addr is a pointer)

or

addr:=Pin_addr(HostEnt.h_addr^)^

if Addr is an in_addr record ?


Michael.