@@ -133,10 +133,9 @@ impl ChangeSet {
133133 Ordering::Greater => {
134134 // figure out the byte index of the truncated string end
135135 let (pos, _) = s.char_indices().nth(j).unwrap();
136− // calculate the difference
137− let to_drop = s.len() - pos;
138− s.pop_back(u32::try_from(to_drop).unwrap());
139− head_a = Some(Insert(s));
136+ let pos = pos as u32;
137+ changes.push(Insert(s.subtendril(0, pos)));
138+ head_a = Some(Insert(s.subtendril(pos, s.len() as u32 - pos)));
140139 head_b = changes_b.next();
141140 }
142141 }
@@ -425,7 +424,7 @@ impl Transaction {
425424 let len = state.doc.len_chars();
426425 let mut acc = Vec::with_capacity(2 * changes.len() + 1);
427426
428− // TODO: verify ranges are ordered and not overlapping.
427+ // TODO: verify ranges are ordered and not overlapping or change will panic.
429428
430429 let mut last = 0;
431430 for (from, to, tendril) in changes {
@@ -445,7 +444,11 @@ impl Transaction {
445444 }
446445 last = to;
447446 }
448− acc.push(Operation::Retain(len - last));
447+
448+ let span = len - last;
449+ if span > 0 {
450+ acc.push(Operation::Retain(span));
451+ }
449452
450453 Self::from(ChangeSet { changes: acc, len })
451454 }
@@ -580,7 +583,7 @@ mod test {
580583 let transaction = Transaction::change(
581584 &state,
582585 // (1, 1, None) is a useless 0-width delete
583− vec![(6, 11, Some("void".into())), (12, 17, None), (1, 1, None)].into_iter(),
586+ vec![(1, 1, None), (6, 11, Some("void".into())), (12, 17, None)].into_iter(),
584587 );
585588 transaction.apply(&mut state);
586589 assert_eq!(state.doc, Rope::from_str("hello void! 123"));