Fix update_lines performance issues

This resolves performance issues with the `update_lines` method that
were caused by excessive updates without underlines or strikeout
present.

This also resolves a bug that was causing the underline and strikeout to
extend beyond the end of line in some rare cases.

This fixes #114.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/term/mod.rs b/src/term/mod.rs
index 3178de4c..48eedef1 100644
--- a/src/term/mod.rs
+++ b/src/term/mod.rs
@@ -1318,7 +1318,9 @@ impl Term {
         lines = min(lines, self.scroll_region.end - origin);
 
         // Scroll between origin and bottom
-        self.grid.scroll_down(&(origin..self.scroll_region.end), lines, &self.cursor.template);
+        let mut template = self.cursor.template;
+        template.flags = Flags::empty();
+        self.grid.scroll_down(&(origin..self.scroll_region.end), lines, &template);
     }
 
     /// Scroll screen up
@@ -1331,7 +1333,9 @@ impl Term {
         let lines = min(lines, self.scroll_region.end - self.scroll_region.start);
 
         // Scroll from origin to bottom less number of lines
-        self.grid.scroll_up(&(origin..self.scroll_region.end), lines, &self.cursor.template);
+        let mut template = self.cursor.template;
+        template.flags = Flags::empty();
+        self.grid.scroll_up(&(origin..self.scroll_region.end), lines, &template);
     }
 
     fn deccolm(&mut self) {