Fix crash

There might be a better way to track cursor state such that these checks
aren't necessary.

2 files changed, 6 insertions, 2 deletions

diff --git a/src/grid.rs b/src/grid.rs
index d62903c9..c3473d8c 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -134,6 +134,10 @@ impl<T> Grid<T> {
         }
     }
 
+    pub fn contains(&self, cursor: &Cursor) -> bool {
+        self.lines > cursor.line && self.cols > cursor.col
+    }
+
     /// Swap two lines in the grid
     ///
     /// This could have used slice::swap internally, but we are able to have
diff --git a/src/term.rs b/src/term.rs
index 45e3cf75..0cb54240 100644
--- a/src/term.rs
+++ b/src/term.rs
@@ -36,7 +36,7 @@ pub struct RenderGrid<'a> {
 
 impl<'a> RenderGrid<'a> {
     fn new<'b>(grid: &'b mut Grid<Cell>, cursor: &'b Cursor, mode: TermMode) -> RenderGrid<'b> {
-        if mode.contains(mode::SHOW_CURSOR) {
+        if mode.contains(mode::SHOW_CURSOR) && grid.contains(cursor) {
             let cell = &mut grid[cursor];
             mem::swap(&mut cell.fg, &mut cell.bg);
         }
@@ -51,7 +51,7 @@ impl<'a> RenderGrid<'a> {
 
 impl<'a> Drop for RenderGrid<'a> {
     fn drop(&mut self) {
-        if self.mode.contains(mode::SHOW_CURSOR) {
+        if self.mode.contains(mode::SHOW_CURSOR) && self.inner.contains(self.cursor) {
             let cell = &mut self.inner[self.cursor];
             mem::swap(&mut cell.fg, &mut cell.bg);
         }