MozillaCompoundTextInfo.updateSelection() doesn't work across paragraphs

[mltony]

Steps to reproduce:

1. Open Thunderbird and press control+n to create a new email.
2. 2. Navigate to message body and type:

   Hello world
   test good bye
   

   Make sure that there are two paragraphs of text. Make sure to type these strings and not paste - for some reason this doesn't reproduce when pasted.
3. Put cursor at letter w of the word world.
4. Open python console and type:

   >>> t = focus.makeTextInfo('caret')
   >>> t.move('character', 10, 'end')
   10
   >>> t.text
   'world\ntest'
   >>> t._start==t._end
   False
   >>> t.updateSelection()
   

Actual behavior:

Only the word "test" is selected.

Expected behavior:

Words "world\ntest" should be selected.

NVDA logs, crash dumps and other attachments:

N/A

System configuration

NVDA installed/portable/running from source:

Running from source

NVDA version:

master

Windows version:

Windows 11

Name and version of other software in use when reproducing the issue:

Thunderbird 102.10.0

Other information about your system:

Other questions

Does the issue still occur after restarting your computer?

Yes

Have you tried any other versions of NVDA? If so, please report their behaviors.

No

If NVDA add-ons are disabled, is your problem still occurring?

Yes

Does the issue still occur after you run the COM Registration Fixing Tool in NVDA's tools menu?

N/A

[mltony]

This appears to be a flaw of IAccessible2 interface. There is no method to select something across paragraphs, and when trying to select something in each paragraph individually, the selection disappears from the other paragraph.

[seanbudd]

@jcsteh - do you have any input on this?

[jcsteh]

This could be solved by having MozillaCompoundTextInfo use the new IAccessibleTextSelectionContainer interface where supported. This is the same interface used by the native app selection feature in browse mode. Note that this is apparently broken in Chromium, so this will need to be treated as unsupported there as we do in browse mode for now.

[jcsteh]

That interface is only supported as of Gecko 118, so it's only going to work once Thunderbird updates thereto; i.e. Thunderbird 118 or later.

[jcsteh]

@mltony, it's not entirely unrelated, but it'd be better not to clutter this NVDA core bug report with non-core questions. The question is probably better directed to nvda-devel or a GitHub discussion. Thanks.