From e2d780f993201a79261bc6bd869c8b4f1dc410ce Mon Sep 17 00:00:00 2001
From: ahkrr
Date: Sun, 6 Jun 2021 21:32:14 +0200
Subject: fix: 2 panics while setting style + off by 1 The panics would occur
 because set_style would draw outside of the the surface. Both occured using
 `find_prev` or `till_prev` In my case the first panic! would appear in a
 terminal with around 80 columns in helix/README.md going to the end of the
 file with `geglf(` the second with `geglfX` The off by one fix ensures that
 `find_nth_prev` starts at the first character to the left

---
 helix-term/src/ui/editor.rs | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

(limited to 'helix-term')

diff --git a/helix-term/src/ui/editor.rs b/helix-term/src/ui/editor.rs
index f47d6c26..8ce9cdc8 100644
--- a/helix-term/src/ui/editor.rs
+++ b/helix-term/src/ui/editor.rs
@@ -261,7 +261,16 @@ impl EditorView {
                         Rect::new(
                             viewport.x + start.col as u16,
                             viewport.y + start.row as u16,
-                            ((end.col - start.col) as u16 + 1).min(viewport.width),
+                            // .min is important, because set_style does a
+                            // for i in area.left()..area.right() and
+                            // area.right = x + width !!! which shouldn't be > then surface.area.right()
+                            // This is checked by a debug_assert! in Buffer::index_of
+                            ((end.col - start.col) as u16 + 1).min(
+                                surface
+                                    .area
+                                    .width
+                                    .saturating_sub(viewport.x + start.col as u16),
+                            ),
                             1,
                         ),
                         selection_style,
@@ -290,7 +299,12 @@ impl EditorView {
                         );
                     }
                     surface.set_style(
-                        Rect::new(viewport.x, viewport.y + end.row as u16, end.col as u16, 1),
+                        Rect::new(
+                            viewport.x,
+                            viewport.y + end.row as u16,
+                            (end.col as u16).min(viewport.width),
+                            1,
+                        ),
                         selection_style,
                     );
                 }
-- 
cgit v1.2.3-70-g09d2