fix: websocket multi-value connection upgrades

[rschmukler]

Fixes an issue where browsers could send keep-alive and Upgrade in the same request causing the ws/upgrade-request? to return false.

[weavejester]

Thank you for the fix! Could you change the commit description to:

Fix websocket multi-value connection upgrades

Fix an issue where browsers could send Keep-Alive and Upgrade in the
same request causing upgrade-request? to return false.

This just makes it more consistent with the other commits in Ring.

[rschmukler]

@weavejester Done! Also changed the impl to handle nil values. Sorry for the noise. Didn't run the tests locally before submitting the PR. Works now!

[weavejester]

So I reviewed this a few days ago, but I forgot to submit the review, and only just noticed that my comment had "Pending" attached to it. So many apologies for the late response.

[weavejester]

What about:

(let [{{:strs [connection upgrade]} :headers} request]
  (and connection upgrade
       (re-find #"\b(?i)upgrade\b" connection)
       (.equalsIgnoreCase "websocket" upgrade)))

Just makes it a little neater and more concise.

[rschmukler]

No problem at all! Yours looks good! I can submit an amended commit tomorrow (about 12 hours) or you're welcome to commit whatever you feel is best.

Cheers!

[rschmukler]

@weavejester I've submitted a new commit with the suggested implementation. Thanks again!