1 files changed, 58 insertions, 6 deletions
diff --git a/src/features/side_by_side.rs b/src/features/side_by_side.rs
index f175fa2a..ac2de08e 100644
--- a/src/features/side_by_side.rs
+++ b/src/features/side_by_side.rs
@@ -1,6 +1,6 @@
 use itertools::Itertools;
 use syntect::highlighting::Style as SyntectStyle;
-use unicode_segmentation::UnicodeSegmentation;
+use unicode_width::UnicodeWidthStr;
 
 use crate::ansi;
 use crate::cli;
@@ -75,12 +75,10 @@ pub fn available_line_width(
 }
 
 pub fn line_is_too_long(line: &str, line_width: usize) -> bool {
-    let line_sum = line.graphemes(true).count();
-
     debug_assert!(line.ends_with('\n'));
-    // `line_sum` is too large because a trailing newline is present,
-    // so allow one more character.
-    line_sum > line_width + 1
+
+    // graphemes will take care of newlines
+    line.width() > line_width
 }
 
 /// Return whether any of the input lines is too long, and a data
@@ -715,4 +713,58 @@ pub mod tests {
             │  2 │b = 2         │  2 │bb = 2        "#,
         );
     }
+
+    #[test]
+    fn test_two_minus_lines_unicode_truncated() {
+        DeltaTest::with_args(&[
+            "--side-by-side",
+            "--wrap-max-lines",
+            "2",
+            "--width",
+            "16",
+            "--line-fill-method=spaces",
+        ])
+        .set_config(|cfg| cfg.truncation_symbol = ">".into())
+        .with_input(TWO_MINUS_LINES_UNICODE_DIFF)
+        .expect_after_header(
+            r#"
+            │  1 │↵ │    │
+            │    │↵ │    │
+            │    │ >│    │"#,
+        );
+
+        DeltaTest::with_args(&[
+            "--side-by-side",
+            "--wrap-max-lines",
+            "2",
+            "--width",
+            "17",
+            "--line-fill-method=spaces",
+        ])
+        .set_config(|cfg| cfg.truncation_symbol = ">".into())
+        .with_input(TWO_MINUS_LINES_UNICODE_DIFF)
+        .expect_after_header(
+            r#"
+            │  1 │↵ │    │
+            │    │↵ │    │
+            │    │ >│    │"#,
+        );
+
+        DeltaTest::with_args(&[
+            "--side-by-side",
+            "--wrap-max-lines",
+            "2",
+            "--width",
+            "18",
+            "--line-fill-method=spaces",
+        ])
+        .set_config(|cfg| cfg.truncation_symbol = ">".into())
+        .with_input(TWO_MINUS_LINES_UNICODE_DIFF)
+        .expect_after_header(
+            r#"
+            │  1 │一↵│    │
+            │    │二↵│    │
+            │    │三 │    │"#,
+        );
+    }
 }