Using a text-editor in gnome-terminal does not send proper AT-SPI2 events when moving the cursor within trailing whitespace on a line. The cursor is always positioned after the last non-blank character on the line (or to the beginning of line, if there are only spaces on the cursor line). This happens in both GNU  NANO and emacs. One strange thing is that cursor movement is reported correctly to AT-SPI, if text attributes on the cursor line are something else than the terminal defaults.

To reproduce:
1) Run emacs in terminal mode (possibly using -nw)
2) Open a new empty buffer in a major-mode which uses a normal face.
3) Type some non-blank characters, vte sends correct AT-SPI events.
4) Type spaces. Now AT-SPI events are not being sent or are sent incorrectly. Neither orca nor brltty notice the cursor movement.
5) Open a file in lisp-interaction mode.
6) Type ; to introduce a comment. Emacs now uses different colours/attributes for printing the following text.
7) Type some spaces. AT-SPI events are now sent as they ought to be. Both orca and brltty notice the cursor movement.

Trailing whitespace should always be reported to AT-SPI. Otherwise it is impossible to edit tabulated data or indent text correctly using some accessibility technology.