Custom DNS set in Client is not used for IP addresses in OkHttp 5.x

[jnh5y]

I found this issue while upgrading from version 4.10.0 to 5.1.0.

It appears that a custom DNS set on a client is never called. Here is a gist with a working test in 4.10.0 and a failing one with 5.1.0.

https://gist.github.com/jnh5y/c1290f4808f9a9b81760de007a58e151

[yschimke]

See https://github.com/square/okhttp/blob/master/CHANGELOG.md#version-500-alpha5

Fix: Don't ask Dns implementations to resolve strings that are already IP addresses.

[yschimke]

See #7073 (review)

[jnh5y]

@yschimke Thank you for the pointer; makes sense. Would you recommend implementing an Interceptor to achieve the same result or doing something else?

[yschimke]

@jnh5y yes, but I guess it depends what you are actually trying to do.

If your custom DNS, should redirect an IP address somewhere else. Use an interceptor.

If you custom DNS just needs to fail DNS, then it feels a bit contrived. So I'm guessing it's not this.

[jnh5y]

@yschimke Thanks. My goal is to prevent connections to various IPs and hostnames. Sounds like an interceptor is the way to go.