1929159 - Caret doesn't appear when taking a focus on design mode from a shadow

Status: NEW

(Core :: DOM: Editor, defect)

Description

[Makoto Kato [:m_kato]]

Step

1. Open https://bug1920859.bmoattachments.org/attachment.cgi?id=9426979
2. Click [design mode]
3. Set focus to document

Result

Caret doesn't appear even if taking a focus. But when typing keyboard, it is inserted.

Expected Result

Show caret. I guess that editor or focus manager doesn't turn on caret.

Comment 1

[Edgar Chen [:edgar]]

I could reproduce on 90, so it doesn't look like a recent regression.

Comment 2

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(Got a cold so that using sick leaves)]

The checkbox is in a shadow. In the design mode, shadow DOMs are not editable unless they have contenteditable in it. Therefore, if an element in the shadow has focus or selection range(s), HTMLEditor needs to keep hiding the caret. However, when (pseudo-)focus is moved from the shadow, i.e., I think Selection is moved into the light DOM, HTMLEditor or Selection needs to run the focus handling only in the design mode. I guess the best place is HTMLEditor::NotifySelectionChanged.