1 files changed, 19 insertions, 1 deletions
diff --git a/helix-core/src/transaction.rs b/helix-core/src/transaction.rs
index e61063f0..085f40b7 100644
--- a/helix-core/src/transaction.rs
+++ b/helix-core/src/transaction.rs
@@ -90,7 +90,8 @@ impl ChangeSet {
             return;
         }
 
-        self.len_after += fragment.len();
+        // Avoiding std::str::len() to account for UTF-8 characters.
+        self.len_after += fragment.chars().count();
 
         let new_last = match self.changes.as_mut_slice() {
             [.., Insert(prev)] | [.., Insert(prev), Delete(_)] => {
@@ -754,4 +755,21 @@ mod test {
         use Operation::*;
         assert_eq!(changes.changes, &[Insert("a".into())]);
     }
+
+    #[test]
+    fn combine_with_utf8() {
+        const TEST_CASE: &'static str = "Hello, これはヒレクスエディターです！";
+
+        let empty = Rope::from("");
+        let mut a = ChangeSet::new(&empty);
+
+        let mut b = ChangeSet::new(&empty);
+        b.insert(TEST_CASE.into());
+
+        let changes = a.compose(b);
+
+        use Operation::*;
+        assert_eq!(changes.changes, &[Insert(TEST_CASE.into())]);
+        assert_eq!(changes.len_after, TEST_CASE.chars().count());
+    }
 }