Ignore MisbehavingServers rather than fail with an error

[Joshua Root]

On 2012-4-9 17:09 , Ryan Schmidt wrote:
> 
> What I'm trying to get across is that if we have an opportunity to reduce the number of tickets that get filed, that's of benefit to everyone, so why shouldn't we do it?

It's questionable that the patch will actually do that. (And you know as
well as I that reducing the number of tickets filed is not in itself of
benefit to everyone.)

> I agree it and a bit of a hack, but I cannot envision a situation in which it doesn't work correctly. If you can, please let me know.

The obvious failure case would be a correctly downloaded file that looks
like HTML to file(1) but doesn't end in .htm[l].

This simply hasn't been tested exhaustively, and it probably isn't
practical to. That alone is a sufficient reason not to want it in the
release.

> Off the top of my head, here's an alternate solution: right before we ping servers to find which ones are nearby, look up the IP address of a hostname that we know doesn't exist (i.e. nonexistent.macports.org). If it returns an IP address, we know we're dealing with a broken DNS server. Then, see if any of the servers we're going to ping resolve to the same IP. If so, they should be removed from the list and treated as if they don't exist.

That and Jeff's idea of using known good DNS servers are certainly worth
investigating.

- Josh