Fix selection starting in first cell

When selecting to the top and starting in the first cell, alacritty
would crash. These cases have been fixed and now selection should be
completely working.

1 files changed, 24 insertions, 1 deletions

diff --git a/src/selection.rs b/src/selection.rs
index d49236a4..f775f1f6 100644
--- a/src/selection.rs
+++ b/src/selection.rs
@@ -279,8 +279,31 @@ impl Selection {
                 });
             }
         } else if start.line < end.line {
-            start.col -= 1;
             end.col += 1;
+            if start.col > Column(0) {
+                start.col -= 1;
+            }
+            // Special case for when a selection is started
+            // in the first cell of a line
+            else {
+                let ty = match end_side {
+                    Side::Left => SpanType::ExcludeTail,
+                    Side::Right => SpanType::Inclusive,
+                };
+
+                // Switch start cell to last cell of previous line
+                if start_side == Side::Left {
+                    start.line += 1;
+                    start.col = cols - 1;
+                }
+
+                return Some(Span {
+                    ty,
+                    cols,
+                    front: start,
+                    tail: end,
+                });
+            }
         }
 
         let (front, tail, front_side, tail_side) = if start > end {