Bug 1878708 - Dialogs HideAllPopoversUntil nearest popover, not docum…

…ent. r=smaug

Given some markup like:

```html
<div id=popover popover>
  <button id="openDialog">Open Dialog</button>
  <dialog id=dialog>
    I'm a dialog!
  </dialog>
</div>
<button id="openPopover">Open Popover</button>
<button>I do nothing!</button>
```

With some JS like

```js
openDialog.onclick = () => {
  dialog.showModal();
}

openPopover.onclick = () => {
  popover.showPopover();
}
```

Clicking the "Open Popover" button followed by the "Open Dialog" button results in both the Dialog and Popover being hidden, however the dialog will still be open as modal, rendering the whole page inert, nothing is clickable and there seems to be no way to undo this (unless you use a CloseWatcher gesture such as the Esc key - if you have one available on your device).

It is expected that the popover should not close the dialog, as it causes the invisible Modal Dialog to make the whole page inert, and it is very difficult for users (and developers) to discover how to undo this action (pressing escape).

This was reported in whatwg/html#9998, and WhatWG resolved to fix this, which in whatwg/html#10116.

Differential Revision: https://phabricator.services.mozilla.com/D200686

UltraBlame original commit: 52284e30cea2c52ab073310e4010161702dc92e4

dom/base/Element.cpp

@@ -22810,6 +22810,8 @@ const
 Element
 *
 aInvoker
+bool
+isPopover
 )
 const
 {
@@ -22863,6 +22865,11 @@ index
 )
 ;
 }
+if
+(
+isPopover
+)
+{
 popoverPositions
 .
 LookupOrInsert
@@ -22871,6 +22878,7 @@ newPopover
 index
 )
 ;
+}
 Element
 *
 topmostPopoverAncestor

dom/base/Element.h

@@ -1910,6 +1910,8 @@ const
 Element
 *
 aInvoker
+bool
+isPopover
 )
 const
 ;

dom/html/HTMLDialogElement.cpp

@@ -275,13 +275,42 @@ StorePreviouslyFocusedElement
 (
 )
 ;
+RefPtr
+<
+nsINode
+>
+hideUntil
+=
+GetTopmostPopoverAncestor
+(
+nullptr
+false
+)
+;
+if
+(
+!
+hideUntil
+)
+{
+hideUntil
+=
+OwnerDoc
+(
+)
+;
+}
 OwnerDoc
 (
 )
 -
 >
-HideAllPopoversWithoutRunningScript
+HideAllPopoversUntil
 (
+*
+hideUntil
+false
+true
 )
 ;
 FocusDialog
@@ -598,13 +627,42 @@ StorePreviouslyFocusedElement
 (
 )
 ;
+RefPtr
+<
+nsINode
+>
+hideUntil
+=
+GetTopmostPopoverAncestor
+(
+nullptr
+false
+)
+;
+if
+(
+!
+hideUntil
+)
+{
+hideUntil
+=
+OwnerDoc
+(
+)
+;
+}
 OwnerDoc
 (
 )
 -
 >
-HideAllPopoversWithoutRunningScript
+HideAllPopoversUntil
 (
+*
+hideUntil
+false
+true
 )
 ;
 FocusDialog

dom/html/HTMLDialogElement.h

@@ -199,6 +199,7 @@ nsAString
 aReturnValue
 )
 ;
+MOZ_CAN_RUN_SCRIPT
 void
 Show
 (
@@ -207,6 +208,7 @@ ErrorResult
 aError
 )
 ;
+MOZ_CAN_RUN_SCRIPT
 void
 ShowModal
 (

dom/html/nsGenericHTMLElement.cpp

@@ -17749,6 +17749,7 @@ ancestor
 GetTopmostPopoverAncestor
 (
 aInvoker
+true
 )
 ;
 if

testing/web-platform/meta/html/semantics/popovers/popover-top-layer-nesting-anchor.tentative.html.ini

@@ -37,18 +37,6 @@ auto
 ancestor
 with
 dialog
-]
-expected
-:
-FAIL
-[
-Single
-popover
-=
-auto
-ancestor
-with
-dialog
 anchor
 attribute
 ]
@@ -89,18 +77,6 @@ manual
 ancestor
 with
 dialog
-]
-expected
-:
-FAIL
-[
-Single
-popover
-=
-manual
-ancestor
-with
-dialog
 anchor
 attribute
 ]
@@ -189,7 +165,6 @@ not
 debug
 :
 NOTRUN
-FAIL
 [
 Nested
 popover
@@ -300,7 +275,6 @@ not
 debug
 :
 NOTRUN
-FAIL
 [
 Nested
 popover
@@ -418,7 +392,6 @@ not
 debug
 :
 NOTRUN
-FAIL
 [
 Top
 layer

testing/web-platform/meta/html/semantics/popovers/popover-top-layer-nesting-hints.tentative.html.ini

@@ -20,18 +20,6 @@ auto
 hint
 ancestors
 with
-dialog
-]
-expected
-:
-FAIL
-[
-Nested
-auto
-/
-hint
-ancestors
-with
 fullscreen
 ]
 expected

testing/web-platform/meta/html/semantics/popovers/popover-top-layer-nesting.tentative.html.ini

@@ -18,18 +18,6 @@ popover
 auto
 ancestor
 with
-dialog
-]
-expected
-:
-FAIL
-[
-Single
-popover
-=
-auto
-ancestor
-with
 fullscreen
 ]
 expected
@@ -42,18 +30,6 @@ popover
 manual
 ancestor
 with
-dialog
-]
-expected
-:
-FAIL
-[
-Single
-popover
-=
-manual
-ancestor
-with
 fullscreen
 ]
 expected
@@ -66,18 +42,6 @@ popover
 auto
 ancestors
 with
-dialog
-]
-expected
-:
-FAIL
-[
-Nested
-popover
-=
-auto
-ancestors
-with
 fullscreen
 ]
 expected
@@ -93,21 +57,6 @@ target
 is
 outer
 with
-dialog
-]
-expected
-:
-FAIL
-[
-Nested
-popover
-=
-auto
-ancestors
-target
-is
-outer
-with
 fullscreen
 ]
 expected
@@ -121,19 +70,6 @@ of
 nested
 element
 with
-dialog
-]
-expected
-:
-FAIL
-[
-Top
-layer
-inside
-of
-nested
-element
-with
 fullscreen
 ]
 expected