Properly fix `last_line` view calculation.

Turned out to be simpler than I thought.  Didn't even need to change the
other use-sites.

1 files changed, 3 insertions, 2 deletions

diff --git a/helix-view/src/view.rs b/helix-view/src/view.rs
index 24df7a4f..ccb61646 100644
--- a/helix-view/src/view.rs
+++ b/helix-view/src/view.rs
@@ -119,8 +119,9 @@ impl View {
     pub fn last_line(&self, doc: &Document) -> usize {
         let height = self.area.height.saturating_sub(1); // - 1 for statusline
         std::cmp::min(
-            self.first_line + height as usize,
-            doc.text().len_lines() - 1,
+            // Saturating subs to make it inclusive zero indexing.
+            (self.first_line + height as usize).saturating_sub(1),
+            doc.text().len_lines().saturating_sub(1),
         )
     }