1939945 - Caret motion into element with overflow-x: auto broken

Status: NEW

(Core :: Layout, defect)

Description

[Marijn Haverbeke]

Attachment: Simple HTML page that reproduces the issue

Moving the caret down with the down arrow key, into a PRE element with an 'overflow-x: auto' style (even when it has no scrollbar) containing multiple lines, will put the cursor at the end of that element, rather than on the first line. This happens both in contenteditable elements and with caret browsing.

This appears to be a recent regression, but I haven't narrowed down the precise Firefox version in which it changed.

Comment 1

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

The severity field is not set for this bug.
:hiro, could you have a look please?

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Comment 2

[Hiroyuki Ikezoe (:hiro)]

I am moving this bug into Layout since Masayuki told me on #DOM matrix channel that moving caret is handled in nsIFrame::PeekBlah functions and he thinks GetNextPrevLineFromBlockFrame is the primary suspect.

Comment 3

[David Shin[:dshin]]

Hm, going as far as 2022-01-01 build I still see the caret landing on the three line.