1636516 - Contenteditable cursors hidden, if other contenteditable-element attached to fragment and then connected to the dom

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[tobias.buschor]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

• i have some contenteditable-elements on the page
• create a fragment
• attache a other contenteditable-element to the fragment
• connect the element to the dom

See here: https://jsfiddle.net/cyLkmxag/58/

Actual results:

all contenteditable-cursors disappear with the exeption of the newly created one

Comment 1

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

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Comment 2

[Alice0775 White]

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=f17b7ba6d0aa737d4f69a0fc3206da8c539225e5&tochange=8e88421b280c2afda62f4ba704ce29701c30549f

Comment 3

[Emilio Cobos Álvarez (:emilio)]

Gah, guess I should've kept my mouth shut! ;)

Thanks a lot Alice :)

Comment 4

[Emilio Cobos Álvarez (:emilio)]

Attachment: testcase from reporter.

Comment 5

[Emilio Cobos Álvarez (:emilio)]

A workaround is to add -moz-user-modify: read-write to the previous element, but I still don't know why its state is borked.

Comment 6

[Emilio Cobos Álvarez (:emilio)]

Attachment: Test-case with hidden attribute instead.

This seems to be a more general problem with sharing of mapped attributes when adopting from a template document, somehow.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1636516 - When moving an element to another document, don't drop nsMappedAttributes from its sheet. r=edgar

The sheet pointer means a very specific thing: This nsMappedAttributes
is registered on nsHTMLStyleSheet. When adopting a node into another
document, we'd call SetStyleSheet on a clone of the attribute, and clear
the actual interesting entry, which means it'd fail to get a declaration
block.

On the original test-case it was about the -moz-user-modify property
that contenteditable maps, but it reproduces with any mapped attribute
like hidden, so I used that for WPT.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/7365c2beddab
When moving an element to another document, don't drop nsMappedAttributes from its sheet. r=edgar

Comment 9

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/23512 for changes under testing/web-platform/tests

Comment 10

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Upstream web-platform-tests status checks passed, PR will merge once commit reaches central.

Comment 11

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/7365c2beddab

Comment 12

[tobias.buschor]

Good job, thank you!

Comment 13

[Web Platform Test Sync Bot (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot