ensure that diffing a screen against itself always returns nothing

3 files changed, 6 insertions, 0 deletions

diff --git a/src/grid.rs b/src/grid.rs
index 9681638..a36491b 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -250,6 +250,7 @@ impl Grid {
     ) -> crate::attrs::Attrs {
         let mut prev_pos = prev.pos;
         let mut wrapping = false;
+        let mut prev_wrapping = false;
         for (i, (row, prev_row)) in
             self.visible_rows().zip(prev.visible_rows()).enumerate()
         {
@@ -261,12 +262,14 @@ impl Grid {
                 self.size.cols,
                 i,
                 wrapping,
+                prev_wrapping,
                 prev_pos,
                 prev_attrs,
             );
             prev_pos = new_pos;
             prev_attrs = new_attrs;
             wrapping = row.wrapped();
+            prev_wrapping = prev_row.wrapped();
         }
 
         self.write_cursor_position_formatted(
diff --git a/src/row.rs b/src/row.rs
index f1c3086..d60d48b 100644
--- a/src/row.rs
+++ b/src/row.rs
@@ -286,6 +286,7 @@ impl Row {
         width: u16,
         row: u16,
         wrapping: bool,
+        prev_wrapping: bool,
         mut prev_pos: crate::grid::Pos,
         mut prev_attrs: crate::attrs::Attrs,
     ) -> (crate::grid::Pos, crate::attrs::Attrs) {
@@ -294,6 +295,7 @@ impl Row {
         let first_cell = self.get(start).unwrap();
         let prev_first_cell = prev.get(start).unwrap();
         if wrapping
+            && !prev_wrapping
             && first_cell == prev_first_cell
             && prev_pos.row + 1 == row
             && prev_pos.col
diff --git a/src/screen.rs b/src/screen.rs
index cec1888..c885242 100644
--- a/src/screen.rs
+++ b/src/screen.rs
@@ -368,6 +368,7 @@ impl Screen {
                     width,
                     i,
                     false,
+                    false,
                     crate::grid::Pos { row: i, col: start },
                     crate::attrs::Attrs::default(),
                 );