From f106b505a39087df01e199905033aa2113ea959a Mon Sep 17 00:00:00 2001
From: mars <mars@tebibyte.media>
Date: Tue, 4 Oct 2022 15:56:42 -0600
Subject: [PATCH] Fix cursor draw out-of-bounds

---
 src/main.rs | 80 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 42 insertions(+), 38 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index ebb3a5b..23033de 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,7 +11,6 @@ use alacritty_terminal::Term;
 use mio_extras::channel::Sender as MioSender;
 use softbuffer::GraphicsContext;
 use std::borrow::Cow;
-use std::collections::HashMap;
 use std::sync::mpsc::{channel, Receiver, Sender};
 use std::sync::Arc;
 use std::thread::JoinHandle;
@@ -79,7 +78,7 @@ impl App {
             },
             ..Default::default()
         };
-        
+
         alacritty_terminal::tty::setup_env(&term_config);
 
         let term_listener = TermListener::new(sender.clone());
@@ -207,55 +206,60 @@ impl App {
             }
         }
 
+        if !missing_chars.is_empty() {
+            log::debug!("Missing characters: {:?}", missing_chars);
+        }
+
         let term_row = content.cursor.point.line.0 as usize;
         let term_col = content.cursor.point.column.0 as usize;
-        let mut px_row = term_row * width * self.cell_height + term_col * self.cell_width;
 
-        let cursor_color = 0x00ff00ff;
+        if (term_row + 1) * self.cell_height < height && (term_col + 1) * self.cell_width < width {
+            let mut px_row = term_row * width * self.cell_height + term_col * self.cell_width;
 
-        use alacritty_terminal::ansi::CursorShape;
-        match content.cursor.shape {
-            CursorShape::Block => {
-                for _y in 0..self.cell_height {
+            let cursor_color = 0x00ff00ff;
+
+            use alacritty_terminal::ansi::CursorShape;
+            match content.cursor.shape {
+                CursorShape::Block => {
+                    for _y in 0..self.cell_height {
+                        for x in 0..self.cell_width {
+                            buffer[px_row + x as usize] = cursor_color;
+                        }
+
+                        px_row += width;
+                    }
+                }
+                CursorShape::Beam => {
+                    for _y in 0..self.cell_height {
+                        buffer[px_row] = cursor_color;
+                        px_row += width;
+                    }
+                }
+                CursorShape::Underline => {
+                    px_row += (self.cell_height - 1) * width;
+                    for x in 0..self.cell_width {
+                        buffer[px_row + x as usize] = cursor_color;
+                    }
+                }
+                CursorShape::HollowBlock => {
                     for x in 0..self.cell_width {
                         buffer[px_row + x as usize] = cursor_color;
                     }
 
-                    px_row += width;
-                }
-            }
-            CursorShape::Beam => {
-                for _y in 0..self.cell_height {
-                    buffer[px_row] = cursor_color;
-                    px_row += width;
-                }
-            }
-            CursorShape::Underline => {
-                px_row += (self.cell_height - 1) * width;
-                for x in 0..self.cell_width {
-                    buffer[px_row + x as usize] = cursor_color;
-                }
-            }
-            CursorShape::HollowBlock => {
-                for x in 0..self.cell_width {
-                    buffer[px_row + x as usize] = cursor_color;
-                }
+                    for _y in 0..(self.cell_height - 1) {
+                        buffer[px_row] = cursor_color;
+                        buffer[px_row + self.cell_width - 1] = cursor_color;
+                        px_row += width;
+                    }
 
-                for y in 0..(self.cell_height - 1) {
-                    buffer[px_row] = cursor_color;
-                    buffer[px_row + self.cell_width - 1] = cursor_color;
-                    px_row += width;
-                }
-
-                for x in 0..self.cell_width {
-                    buffer[px_row + x as usize] = cursor_color;
+                    for x in 0..self.cell_width {
+                        buffer[px_row + x as usize] = cursor_color;
+                    }
                 }
+                CursorShape::Hidden => {}
             }
-            CursorShape::Hidden => {}
         }
 
-        log::debug!("Missing characters: {:?}", missing_chars);
-
         self.graphics
             .set_buffer(&buffer, width as u16, height as u16);
     }