OK response after too-long URL?

[cceckman-at-fastly]

We've seen stderr logs from requests with long URLs that report:

Exception while initialization of FetchEvent
Error: init_request: Buffer length error. Buffer is too long.

These seem to come from here and (presumably) somewhere around here.

The big problem is that these requests were still returning 200s (!)

We should work to reproduce, and chase down whether this is an SDK bug or a platform bug.

(One point of bisection: I ran a Rust service that had a long URL, but that didn't request it in the guest- and it completed fine. So it's likely that it's either within the guest, or on the guest/host boundary, i.e. host unwilling to copy the URL to the guest.)