Revert "don't cache more than 1024 entries, to avoid DoS attacks"

[grandcat]

Reverts #94

Causes 2/2 test runs to fail (race) or even crash on master.
@marten-seemann fyi

[marten-seemann]

That's a manifestation of #98, namely the fact that with the current API, there's no way to tell when the mainloop go routine has shut down.

#100 should fix that race condition by reworking the client-side API.

What the test does and what causes the race condition is reduce this value, to speed up the test:

zeroconf/client.go

Lines 29 to 30 in 60421fc

	// DoS protection: we won't cache more than 1024 entries when receiving entries.
	var maxSentEntries = 1024

Once the test is done, it resets it to the old value. Problem is, as mainloop exits eventually after the context is canceled, it may still read from that variable.

[grandcat]

Thanks for the explanation.
In any case, it increases changes for failing tests on master. Therefore, I'd prefer reverting this Pr until we have a more stabilized version, may it be a change in client.go, may it be a slightly different test case.

[marten-seemann]

I don't think there's a lot we can do to fix the test case, other than adding ridiculous long sleeps. Is there any chance we can get #100 merged any time soon?