As part of #1405, we changed the way we performed undo and redo to
support combining transactions that were not temporally adjacent for
IME purposes.
We introduced a bug with that release that caused divergence
when performing undo: the bug was caused by only changing the visibility
of fragments whose insertion id was contained in the undo operation. However,
an undo operation also affects deletions which we were mistakenly not
considering. Randomized tests caught this but I guess we didn't run enough
of them.
Now, instead of using these versioned offset ranges, we locate the
fragments associated with a transaction using the transaction's
edit ids. To make this possible, buffers now store a new map called
`insertion_slices`, which lets you look up the ranges of insertions
that were affected by a given edit.
Co-authored-by: Antonio Scandurra <antonio@zed.dev>
* Moving the logic from Rope to text::Buffer makes it easier
to keep the Rope in sync with the fragment tree.
* Removing carriage return characters is lossier, but is much
simpler than incrementally maintaining the invariant that
there are no carriage returns followed by newlines. We may
want to do something smarter in the future.
Co-authored-by: Keith Simmons <keith@zed.dev>
This is calculated in `Rope` and uses the `bromberg_sl2` homomorphic
hash function to determine the fingerprint of a single chunk and
compose each chunk fingerprint into a single fingerprint for the entire
rope that is equivalent to hashing all the rope's bytes at once.
* Add a `hard_tabs` setting that causes indentation to be performed
using a tab instead of multiple spaces.
* Change Buffer's indentation-related APIs to return an `IndentSize`
struct with a length and a kind, instead of just a single u32.
* Use hard tabs by default in Go.
Previously, buffer edits represented empty strings as None
variants of an Option. Now, the edit logic just explicitly
checks for empty strings.
Co-authored-by: Keith Simmons <keith@zed.dev>
We forgot to observe the footprint of the reconnecting replica's prior
undos into the local clock. This could cause the replica to generate
edits with a version strictly smaller than what other peers may have
observed. As such, those peers would think they had already seen those
edits and skip them.
These completions don't supply a range that should be overwritten, so
the client needs to infer it via substring matching.
Co-authored-by: Keith Simmons <keith@zed.dev>
