From b97187c90b5a12624e6c5acdea772cabdbcf61d6 Mon Sep 17 00:00:00 2001
From: Johannes Altmanninger <aclopte@gmail.com>
Date: Sun, 7 Apr 2024 08:26:45 +0200
Subject: [PATCH] Fix crash displaying CSI u codepoints in ASCII control range

---
 src/key.rs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/key.rs b/src/key.rs
index 36cd4de66..2d9d692eb 100644
--- a/src/key.rs
+++ b/src/key.rs
@@ -414,8 +414,11 @@ fn ascii_printable_to_symbol(buf: &mut WString, c: char) {
 fn char_to_symbol(c: char) -> WString {
     let mut buff = WString::new();
     let buf = &mut buff;
-    assert!(c >= ' ');
-    if c < '\u{80}' {
+    if c <= ' ' {
+        // Most ascii control characters like \x01 are canonicalized like ctrl-a, except if we
+        // are given the control character directly with CSI u.
+        sprintf!(=> buf, "\\x%02x", u8::try_from(c).unwrap());
+    } else if c < '\u{80}' {
         // ASCII characters that are not control characters
         ascii_printable_to_symbol(buf, c);
     } else if fish_wcwidth(c) > 0 {