What is the issue with the HTML Standard?

Here's the problematic scenario:

<div popover="hint"></div>
<script>
const popover = document.querySelector("div");
popover.showPopover();
popover.setAttribute("popover","auto");
</script>

When the popover is shown, its opened in popover mode is set to "hint".
Upon changing the popover attribute:

1. The popover attribute change steps say to run the hide popover algorithm.
2. The hide popover steps eventually say If element's popover attribute is in the auto state or the hint state, then: Run hide all popovers until given element (step 7.1).
3. The hide all popovers until steps eventually say If document's showing hint popover list contains endpoint: Assert: endpoint's popover attribute is in the hint state (step 6.1)
4. That assertion fails because the popover's opened in popover mode is still "hint" (so it is in the document's showing hint popover list), but its popover attribute has been changed to "auto".

After thinking about this, I think the hide popover algorithm should be using the popover's opened in popover mode instead of the current popover state.

After thinking about this, I think the hide popover algorithm should be using the popover's opened in popover mode instead of the current popover state.

Yep, I think this is the proper fix. Chromium indeed doesn't look at the attribute value, but instead the popover mode.

I'd love to submit a fix for this (and my other popover issues) but I can't contribute without publishing my full legal name, which I don't feel comfortable doing. (I believe it would also be legally dubious to give a to someone to submit on my behalf)
So I would really appreciate it if someone else could contribute these (fairly simple) fixes instead.

Thanks for figuring this out! Here's a PR: #11197