Fix panic when using surround_replace/delete (#9796)

1. Create a document containing `{A}`
1. C-w v # vsplit
1. gl    # goto_line_end
1. b     # move_prev_word_start
1. `     # switch_to_lowercase
1. mrm(  # surround replace
1. C-w v # vsplit

In the debug build surround_replace/delete will immedately assert with
`assertion failed: last <= from', transaction.rs:597:13`. The splits and
lowercase conversion are not needed to trigger the bug.

In the release build the surround becomes `)a(` and the last vsplit
causes the transaction to panic.
`internal error: entered unreachable code:
(Some(Retain(18446744073709551573)))', transaction.rs:185:46`

Since the selection direction is backwards get_surround_pos returns the
pairs reversed but the downstream code assumes they are in the forward
direction.

0 files changed, 0 insertions, 0 deletions