fix(terminal): render halfwidth katakana voiced marks (#2257)

Co-authored-by: oyoguhito <oyoguhito@kamatanoMacBook-Pro.local>
Co-authored-by: Can Celik <ogulcancelik@gmail.com>

1 files changed, 71 insertions, 1 deletions

diff --git a/src/server/headless.rs b/src/server/headless.rs
index b4f433f7..859e02af 100644
--- a/src/server/headless.rs
+++ b/src/server/headless.rs
@@ -4910,7 +4910,8 @@ mod tests {
     use super::*;
 
     use crate::app::AppState;
-    use crate::protocol::CursorState;
+    use crate::protocol::{CellData, CursorState};
+    use unicode_width::UnicodeWidthStr;
 
     #[path = "pane_graphics.rs"]
     mod pane_graphics_tests;
@@ -5350,6 +5351,16 @@ mod tests {
         for (idx, (actual_cell, expected_cell)) in
             actual.cells.iter().zip(expected.cells.iter()).enumerate()
         {
+            if cells_equivalent_for_frame_compare(
+                &actual.cells,
+                &expected.cells,
+                usize::from(actual.width),
+                idx,
+                actual_cell,
+                expected_cell,
+            ) {
+                continue;
+            }
             assert_eq!(
                 actual_cell,
                 expected_cell,
@@ -5360,6 +5371,65 @@ mod tests {
         }
     }
 
+    fn cells_equivalent_for_frame_compare(
+        actual_cells: &[CellData],
+        expected_cells: &[CellData],
+        width: usize,
+        idx: usize,
+        actual: &CellData,
+        expected: &CellData,
+    ) -> bool {
+        if actual == expected {
+            return true;
+        }
+        if !cell_style_without_symbol_eq(actual, expected) {
+            return false;
+        }
+        if !matches!(
+            (actual.symbol.as_str(), expected.symbol.as_str()),
+            ("", " ") | (" ", "")
+        ) {
+            return false;
+        }
+        covered_by_previous_wide_cell(actual_cells, width, idx)
+            || covered_by_previous_wide_cell(expected_cells, width, idx)
+    }
+
+    fn cell_style_without_symbol_eq(a: &CellData, b: &CellData) -> bool {
+        a.fg == b.fg
+            && a.bg == b.bg
+            && a.modifier == b.modifier
+            && a.skip == b.skip
+            && a.hyperlink == b.hyperlink
+    }
+
+    fn covered_by_previous_wide_cell(cells: &[CellData], width: usize, idx: usize) -> bool {
+        if idx == 0 || idx.is_multiple_of(width) {
+            return false;
+        }
+        frame_cell_display_width(&cells[idx - 1]) > 1
+    }
+
+    fn frame_cell_display_width(cell: &CellData) -> usize {
+        if is_halfwidth_katakana_voiced_grapheme(&cell.symbol) {
+            return 2;
+        }
+        cell.symbol.width()
+    }
+
+    fn is_halfwidth_katakana_voiced_grapheme(symbol: &str) -> bool {
+        let mut chars = symbol.chars();
+        let Some(base) = chars.next() else {
+            return false;
+        };
+        let Some(mark) = chars.next() else {
+            return false;
+        };
+        chars.next().is_none()
+            && ('\u{ff66}'..='\u{ff9d}').contains(&base)
+            && matches!(mark, '\u{ff9e}' | '\u{ff9f}')
+    }
+
     #[test]
     fn foreground_client_applies_client_keybindings() {
         let mut server = test_headless_server();