From cab27fc4ead3becc39185443dfa1f2fb51291fa4 Mon Sep 17 00:00:00 2001
From: Jesse Luehrs <doy@tozt.net>
Date: Fri, 12 Nov 2021 15:30:59 -0500
Subject: handle backspacing over combined characters properly

---
 Cargo.lock      | 1 +
 Cargo.toml      | 1 +
 src/readline.rs | 7 ++++++-
 3 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/Cargo.lock b/Cargo.lock
index 77c5df0..1edc916 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -385,6 +385,7 @@ dependencies = [
  "signal-hook-async-std",
  "terminal_size",
  "textmode",
+ "unicode-width",
  "vt100",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 9e1c444..e5cb362 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -16,6 +16,7 @@ signal-hook = "0.3.10"
 signal-hook-async-std = "0.2.1"
 terminal_size = "0.1.17"
 textmode = { path = "../textmode", version = "0.1.1", features = ["async"] }
+unicode-width = "0.1.9"
 vt100 = { path = "../vt100-rust", version = "0.12.0" }
 
 [features]
diff --git a/src/readline.rs b/src/readline.rs
index ff5f9a9..37fc054 100644
--- a/src/readline.rs
+++ b/src/readline.rs
@@ -1,4 +1,5 @@
 use textmode::Textmode as _;
+use unicode_width::UnicodeWidthChar as _;
 
 pub struct Readline {
     size: (u16, u16),
@@ -74,7 +75,11 @@ impl Readline {
     }
 
     fn backspace(&mut self) {
-        self.input_line.pop();
+        let mut width = 0;
+        while width == 0 {
+            width =
+                self.input_line.pop().map_or(1, |c| c.width().unwrap_or(0));
+        }
     }
 
     fn clear_input(&mut self) {
-- 
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