remove disconnected autoPopovers during topMostPopoverAncestor algo

Prior to this change, a popover removed from the document would still be
in the autoPopovers set, and subsequently `topMostPopverAncestor` would
return disconnected elements, causing `closeAllPopovers` to hit an
infinite loop:

1. `hidePopover` is called
2. `closeAllPopovers` is called
3. `topMostPopoverAncestor` is called and returns disconnected element.
4. `hidePopover(topMost)` is called but returns false, as the element is
   disconnected.
5. `topMostPopoverAncestor` is called, but it returns the same element.
   Repeat step 4, infinite loop.

This commit alters `topMostAutoPopover` to check if the element is
disconnected, and remove it from the set if so, only returning the first
connected element.

1. `hidePopover` is called
2. `closeAllPopovers` is called
3. `topMostPopoverAncestor` is called, the first element is
   disconnected, so it skips and returns the first connected element.
4. `hidePopover(topMost)` is called and returns true.
5. No infinite loop.

src/popover-helpers.ts

@@ -75,7 +75,15 @@ function topMostClickedPopover(target: HTMLElement) {
 
 // https://html.spec.whatwg.org/#topmost-auto-popover
 function topMostAutoPopover(document: Document): HTMLElement | null {
-  return Array.from(autoPopoverList.get(document) || []).pop() || null;
+  const documentPopovers = autoPopoverList.get(document);
+  for (const popover of documentPopovers || []) {
+    if (!popover.isConnected) {
+      documentPopovers.delete(popover);
+    } else {
+      return popover;
+    }
+  }
+  return null;
 }
 
 // https://html.spec.whatwg.org/#nearest-inclusive-open-popover

tests/edge-cases.spec.ts

@@ -0,0 +1,22 @@
+import { expect, test } from '@playwright/test';
+
+test.beforeEach(async ({ page }) => {
+  await page.goto('/');
+});
+
+test('removing an autoPopover from document doesnt crash page', async ({
+  page,
+}) => {
+  const popover = (await page.locator('#popover1')).nth(0);
+  await expect(popover).toBeHidden();
+  await expect(
+    await popover.evaluate((node) => node.showPopover()),
+  ).toBeUndefined();
+  await expect(popover).toBeVisible();
+  await expect(await popover.evaluate((node) => node.remove())).toBeUndefined();
+  const popover2 = (await page.locator('#popover2')).nth(0);
+  await expect(
+    await popover2.evaluate((node) => node.showPopover()),
+  ).toBeUndefined();
+  await expect(popover2).toBeVisible();
+});