From 601547b83da75eb0364dc6edd53b3a569ddca848 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Wed, 19 Oct 2022 16:09:22 -0600
Subject: [PATCH] Improved backspace

---
 examples/editor-test/src/main.rs |  4 ++--
 src/buffer.rs                    | 20 +++++++++++++++-----
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/examples/editor-test/src/main.rs b/examples/editor-test/src/main.rs
index b20897f..c9acc57 100644
--- a/examples/editor-test/src/main.rs
+++ b/examples/editor-test/src/main.rs
@@ -137,6 +137,8 @@ fn main() {
 
     //TODO: support bidi
     for line in text.lines() {
+        log::debug!("Line {:?}", line);
+
         for c in line.chars() {
             if c.is_control() {
                 log::warn!("Ignoring control character {:?}", c);
@@ -167,8 +169,6 @@ fn main() {
             buffer.action(TextAction::Insert(c));
         }
 
-        log::debug!("Line '{}': {:?}", line, line);
-
         // Test backspace of newline
         {
             let cursor = buffer.cursor();
diff --git a/src/buffer.rs b/src/buffer.rs
index 393214e..55da9b3 100644
--- a/src/buffer.rs
+++ b/src/buffer.rs
@@ -473,21 +473,31 @@ impl<'a> TextBuffer<'a> {
                     text_line.remove(glyph.start);
                     self.reshape_line(line.line_i);
                 } else if self.cursor.line > 0 {
-                    self.cursor.glyph = self.layout_lines[self.cursor.line - 1].glyphs.len();
-
                     {
                         let line = &self.layout_lines[self.cursor.line];
-                        let old_line = self.text_lines.remove(line.line_i.get());
-                        self.text_lines[line.line_i.get() - 1].push_str(&old_line);
+                        let prev_line = &self.layout_lines[self.cursor.line - 1];
+                        if prev_line.line_i.get() < line.line_i.get() {
+                            let old_line = self.text_lines.remove(line.line_i.get());
+                            self.text_lines[prev_line.line_i.get()].push_str(&old_line);
+                        } else {
+                            match prev_line.glyphs.last() {
+                                Some(glyph) => {
+                                    let text_line = &mut self.text_lines[line.line_i.get()];
+                                    text_line.remove(glyph.end);
+                                },
+                                None => (), // There should always be a last glyph
+                            }
+                        }
 
                         // Reshape all lines after new line
                         //TODO: improve performance
-                        self.shape_lines.truncate(line.line_i.get() - 1);
+                        self.shape_lines.truncate(prev_line.line_i.get());
                         self.relayout();
                         self.shape_until_scroll();
                     }
 
                     self.cursor.line -= 1;
+                    self.cursor.glyph = self.layout_lines[self.cursor.line].glyphs.len();
 
                     let lines = self.lines();
                     if (self.cursor.line as i32) < self.scroll