fix(multicursor): undo corrupted by insert that changes line-count #41835

Problem:
Undo "u" is wrong after cascading an insert that adds a line (`A{<CR>`, `o`, …).

The cascade replays the insert as a per-cursor `edit()`, where `u_save`
stores a line multiple times into the undo block at different line
counts; then `getbot` computes conflicting entries that undo each other.

Solution:
`u_save` the whole affected line-range as one entry at session start,
the same approach used by Vim for linewise ops (`op_shift`, `ex_sort`).
The "enclosing" `u_save` wins and the invalid entries are overridden.

0 files changed, 0 insertions, 0 deletions