2015380 - Windows 11 Text Cursor Indicator is positioned in message body instead of To: field when composing a new message in Thunderbird

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[James Teh [:Jamie]]

Spun off bug 2012252 comment 12.

STR:

1. Turn on Text Cursor Indicator in Settings.
2. Compose a new message in Thunderbird.
3. Observe that the "To:" field is focused.
   • Expected: The Text Cursor Indicator should be positioned in the "To:" field.
   • Actual: The Text Cursor Indicator is positioned in the message body.
4. Type some text.
   • Result: The Text Cursor Indicator is correctly positioned in the "To:" field.

Comment 1

[James Teh [:Jamie]]

https://treeherder.mozilla.org/jobs?repo=try&revision=e1a9b6959bb8ebfee807dbb1b80130d500623b85

Comment 2

[BugBot [:suhaib / :marco]]

Set release status flags based on info from the regressing bug 2006816

Comment 3

[James Teh [:Jamie]]

Attachment: Bug 2015380 part 1: Refactor code to get the caret rect for IPC events into a function which can be called from elsewhere. r?eeejay!

Previously, this was a lambda, but we will soon need to call it from SelectionManager as well.

Comment 4

[James Teh [:Jamie]]

Attachment: Bug 2015380 part 2: Don't fire a caret event when the caret moves within a document which isn't focused. r?eeejay!

Firing a caret event for an Accessible which doesn't have focus confuses clients, who expect that the caret should be related to the focus.
Prior to bug 2006816, this wasn't as bad because even though we fired the caret event on the wrong Accessible, TextLeafPoint::GetCaret still returned the caret from the focused document.
After bug 2006816, we use the cached caret, so the event and the retrieved caret are both (consistently) incorrect.
To fix this:

1. Make it possible to update the RemoteAccessible cache for the caret via IPDL without firing a caret event.
2. When the caret moves, don't fire a caret event unless it's within the focused document.
3. However, the caret event won't be fired again when the document eventually gets focused, so we still send an IPDL message to update the cached caret in the RemoteAccessible tree.
4. In TextLeafPoint::GetCaret, only use the cached caret if the cached caret Accessible is within the same document as the origin Accessible.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/5d5c20208b8c
https://hg.mozilla.org/integration/autoland/rev/08bf13d30134
part 1: Refactor code to get the caret rect for IPC events into a function which can be called from elsewhere. r=eeejay
https://github.com/mozilla-firefox/firefox/commit/4d33b2b2c24b
https://hg.mozilla.org/integration/autoland/rev/f39bae80701f
part 2: Don't fire a caret event when the caret moves within a document which isn't focused. r=eeejay

Comment 6

[amarc]

https://hg.mozilla.org/mozilla-central/rev/08bf13d30134
https://hg.mozilla.org/mozilla-central/rev/f39bae80701f

Comment 7

[BugBot [:suhaib / :marco]]

The patch landed in nightly and beta is affected.
:Jamie, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
  • See https://wiki.mozilla.org/Release_Management/Requesting_an_Uplift for documentation on how to request an uplift.
• If no, please set status-firefox148 to wontfix.

For more information, please visit BugBot documentation.

Comment 8

[James Teh [:Jamie]]

Caret stuff is obscure, difficult to get right and is historically an area that tends to regress easily. Too risky for beta.