Fetch ignores context timeout.

[andreib1]

nats.go version: 1.13.3
nats version: 2.6.1

I have examined at the Fetch code in js.go and I think there may be some issues with the logic:

When a context is passed in that has a context timeout, and no explicit PullOpts timeout, the code sets the internal ttl to the default timeout value. It uses this default value ttl to time out the request returning context.DeadlineExceeded thereby ignoring the context timeout value.

When a timeout value is provided through PullOpts without a context, the timeout value is respected.

The check at the start of the function prevents supplying both, so therefore it is therefore impossible to provide a cancellable context to Fetch, and and also a timeout.

Providing no timeout value is causing Fetch to stall for us, but I also need to be able to cancel the context during a graceful shutdown of the server.

[andreib1]

At the point of testing the following:

if ttl < 0 {
  // At this point consider that we have timed-out
  return context.DeadlineExceeded
}

Maybe I'm incorrect, but a context has already been assured with a timeout value. If that's right, shouldn't this just check for the context being invalidated instead of ttl?

[wallyqs]

@andreib1 thanks again for the report! This is now fixed in the main branch.