Fix boundary condition in buffer_line_len when at the end of a file

Mikayla Maki and max created 2 years ago

co-authored-by: max <[e-mail]>

Change summary

crates/editor/src/display_map.rs  | 2 +-
crates/editor/src/editor.rs       | 1 -
crates/editor/src/multi_buffer.rs | 6 +++++-
3 files changed, 6 insertions(+), 3 deletions(-)

Detailed changes

crates/editor/src/display_map.rs

@@ -641,7 +641,7 @@ impl DisplaySnapshot {
             return false;
         }
 
-        for next_row in (buffer_row + 1)..max_row {
+        for next_row in (buffer_row + 1)..=max_row {
             let (next_indent_size, next_line_is_blank) = self.line_indent_for_buffer_row(next_row);
             if next_indent_size > indent_size {
                 return true;

crates/editor/src/editor.rs

@@ -5772,7 +5772,6 @@ impl Editor {
 
     pub fn fold_at(&mut self, fold_at: &FoldAt, cx: &mut ViewContext<Self>) {
         let buffer_row = fold_at.buffer_row;
-
         let display_map = self.display_map.update(cx, |map, cx| map.snapshot(cx));
 
         if let Some(fold_range) = display_map.foldable_range(buffer_row) {

crates/editor/src/multi_buffer.rs

@@ -2194,7 +2194,11 @@ impl MultiBufferSnapshot {
 
     pub fn buffer_line_for_row(&self, row: u32) -> Option<(&BufferSnapshot, Range<Point>)> {
         let mut cursor = self.excerpts.cursor::<Point>();
-        cursor.seek(&Point::new(row, 0), Bias::Right, &());
+        let point = Point::new(row, 0);
+        cursor.seek(&point, Bias::Right, &());
+        if cursor.item().is_none() && *cursor.start() == point {
+            cursor.prev(&());
+        }
         if let Some(excerpt) = cursor.item() {
             let overshoot = row - cursor.start().row;
             let excerpt_start = excerpt.range.context.start.to_point(&excerpt.buffer);