Gecko dispatches multiple FocusEvent
s if the focus stayed within the same ShadowRoot and there
shouldn't be a change to document.activeElement
. At least that's my interpretation of
Shadow DOM 5.8 Event Dispatch:
If the relatedTarget and target are the same for a given node, its the event listeners must not be invoked.
This issue may be related to wrong activeElement when focusing element in ShadowDOM and even more so to focus and blur events should have relatedTarget.
In Firefox the setting dom.webcomponents.enabled
needs to be set to true
to enable ShadowDOM support.