DNS: Fix return value for successful name resolutions

[bulislaw]

Description

DNS name resolution was returning error even for successful cases

Status

READY

CC: @geky @0xc0170

[0xc0170]

+1

[geky]

There was an unrelated change to this function that slightly changed the logic. Are you sure the dns_scan_response's return value doesn't need to be checked for a valid match?

[bulislaw]

Yeah you're probably right, we should still return error when the count is 0.

[sg-]

/morph test

[mbed-bot]

Result: SUCCESS

Your command has finished executing! Here's what you wrote!

/morph test

Output

mbed Build Number: 1078

All builds and test passed!

[kjbracey]

Don't like using "!" for non-boolean values. "== 0" would have been clearer.

Also, you end up querying every DNS server when the destination doesn't exist (like 5.1 did). The point of extra DNS servers is to provide a backup if one goes down, not to get second opinions.

And you return "OK" if no servers respond.

Better fix is:

 if (dns_scan_response(&response, addr, addr_count) > 0) {
      result = NSAPI_ERROR_OK;
 }
break;