* Add a undo/redo split test case for crossing branches
* history: Switch up/down transaction chaining order
The old code tends to work in practice because, usually, either up_txns
or down_txns are empty. When both have contents though, we can run into
a panic trying to compose them all since they will disagree on the
length of the text. This fixes the panic test case in the parent
commit.
* Add a test case for updating jumplists across windows
* Apply transactions to all views on history changes
This ensures that jumplist selections follow changes in documents, even
when there are multiple views (for example a split where both windows
edit the same document).
* Leave TODOs for cleaning up View::apply
* Use Iterator::reduce to compose history transactions
Co-authored-by: Blaž Hrastnik <blaz@mxxn.io>
Co-authored-by: Blaž Hrastnik <blaz@mxxn.io>
