Invalid? "Current completion changed before returning" warning

[AntoineGS]

I have been seeing this a lot in the LSP warnings for the github.lua NeoVim plugin (zbirenbaum/copilot.lua#399) and I believe I have found the issue.
It would affect all implementations from what I can see.
The culprit code:

        if (u !== f.clientCompletionId) {
            let be = f.getCompletionsForUserTyping(S, I.prompt.suffix);
            if (be && be.length > 0) return so.warn(e, "Current completion changed before returning"), {
                type: "canceled",
                reason: "current completion changed before returning",
                telemetryData: pd(X)
            }
        }

When the warning is triggered, u is undefined, causing the comparison to fail as if there was already a request (there isn't) and seemingly cancelling the new request.

Update, it seems the issue is not completely resolved by simply checking for null, as the previous uuid seems sticky in some situations.

[devm33]

@AntoineGS could you share more of your logs (without anything sensitive of course) to get the reproduction steps.

as if there was already a request (there isn't)

I'm struggling to see how it could hit this without more than one inline completion request 🤔

[AntoineGS]

Ah shoot, you are right, there was another client hooking up to the same LSP connection also running requests >_<
Thanks for the surprisingly quick reply though!