Does D_EXTEND need a correction in how it uses DnsProvider ?

[Ishan Jain]

Hello everyone! 

I can specify D_EXTEND like this, 

```

D("example.com", DnsProvider(DSP_ADGUARDHOME_HOME),

// RecA

);

D_EXTEND("direct.home.example.com", DnsProvider(DSP_ADGUARDHOME_HOME), DnsProvider(DSP_ADGUARDHOME_DEL),

// RecB

);

```

The way I just assumed this would work is,

1. RecA on example.com would be added to _HOME DnsProvider.

2. RecB on direct.home.example.com would be added to _DEL + _HOME DnsProviders. 

However, this is not how it works. It populates the global dns_providers array and RecB and RecA are all added to _HOME and _DEL! This is unexpected. 

My question is, should this behavior be corrected ? I really think D_EXTEND should work the way I just expected it to work and populating the global dns_providers array that is only used in a D_EXTEND is not quite right 

[Ishan Jain]

In the examples, it does not use D_EXTEND the way I use it so the current design makes sense but then the way I am using it does not generate any errors. 

I think if there is agreement, I'd like to extend D_EXTEND to add the behavior I am referring to.

[Ishan Jain]

Please disregard this. My intent was to get split horizon setup working where example.com has a few public records and a subdomain home.example.com has public + internal records. 

This is easily done with the tags system in `D()` method and we don't need to complicate `D_EXTEND` 

Thanks for reading!

Regards

- Ishan