1732599 - First word of a shadow DOM with slots is not selectable by double-clicking

Status: NEW

(Core :: DOM: Selection, defect, P2)

Description

[Karl Dubost💡 :karlcow]

1. Go to https://mrotherguy.github.io/fx-nightly-changelog/
2. Select a day with the date picker to make sure to have content.
3. A table appears
4. Go to the first word of the description (after bug number and category)
5. Double click on the first word

Expected:
Word is being selected

Actual
Word is not selected

6. Head to the second word
7. Double click

Actual:
Word is being selected.

Comment 1

[Mirko Brodesser (:mbrodesser) -- not reading bugmails currently]

When double-clicking the first word, the Selection is the following:

Selection { anchorNode: #text, anchorOffset: 12, focusNode: #text, focusOffset: 12, isCollapsed: true, rangeCount: 1

That is, a collapsed range after the first word is selected.

Comment 2

[Mirko Brodesser (:mbrodesser) -- not reading bugmails currently]

Changing severity to S2 because major functionality is affected.

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

Change the status for beta to have the same as nightly and release.
For more information, please visit auto_nag documentation.

Comment 4

[Monica Chiorean]

I was able to reproduce the issue using Nightly from 3July 2018, older build than this do not load the change log page (https://mrotherguy.github.io/fx-nightly-changelog/).

Comment 5

[Hsin-Yi Tsai (she/her) [:hsinyi]]

Does this really impact "every" first word in "every" Shadow DOM? The next step here would be to come up with a minimized test case to understand better how widely this impacts Shadow DOM.

Comment 6

[Mirko Brodesser (:mbrodesser) -- not reading bugmails currently]

Minimal example with custom elements:
https://jsfiddle.net/k3Lv748s/1/
The <a> element is necessary.

When using a pure shadow DOM with a template with one slot, none of the words are selected:
https://jsfiddle.net/rscjfz3y/1/

When we fix this, both scenarios require testing.

Comment 7

[Hsin-Yi Tsai (she/her) [:hsinyi]]

It's not ideal that double-clicking doesn't work for certain scenarios. We thought S3 is reasonable - given that the word is still selectable by dragging.