fish_key_reader: use char_to_symbol for verbose output

byte_to_symbol was broken because it didn't iterate by byte, it
iterated by rust-char, which is a codepoint.

So it failed for everything outside of ascii and, because of a
mistaken bound, ascii chars from 0x21 to 0x2F ("!" to "/" - all the punctuation).

char_to_symbol will print printable codepoints as-is and
others escaped. This is okay - something like `decoded from: +` or
`decoded from: ö` is entirely understandable, there is no need to tell
you that "ö" is \xc3\xb6.

This reverts commit 423e5f6c03.

src/bin/fish_key_reader.rs

@@ -20,7 +20,7 @@ use fish::{
     eprintf, fprintf,
     input::input_terminfo_get_name,
     input_common::{terminal_protocols_enable_ifn, CharEvent, InputEventQueue, InputEventQueuer},
-    key::{self, byte_to_symbol, Key},
+    key::{self, char_to_symbol, Key},
     panic::panic_handler,
     print_help::print_help,
     printf,
@@ -104,7 +104,7 @@ fn process_input(continuous_mode: bool, verbose: bool) -> i32 {
         if verbose {
             printf!("# decoded from: ");
             for byte in kevt.seq.chars() {
-                printf!("%s", &byte_to_symbol(byte));
+                printf!("%s", &char_to_symbol(byte));
             }
             printf!("\n");
         }

src/key.rs

@@ -418,7 +418,7 @@ fn ctrl_to_symbol(buf: &mut WString, c: char) {
     // 2. key names that are given as raw escape sequence (\e123); those we want to display
     // similar to how they are given.
 
-    let ctrl_symbolic_names: [&wstr; 28] = {
+    let ctrl_symbolic_names: [&wstr; 29] = {
         std::array::from_fn(|i| match i {
             8 => L!("\\b"),
             9 => L!("\\t"),
@@ -453,26 +453,15 @@ fn ascii_printable_to_symbol(buf: &mut WString, c: char) {
     }
 }
 
-pub fn byte_to_symbol(c: char) -> WString {
-    let mut buff = WString::new();
-    let buf = &mut buff;
-    if c <= '\x1b' {
-        ctrl_to_symbol(buf, c);
-    } else if ('\u{30}'..'\u{7f}').contains(&c) {
-        // ASCII characters that are not control characters
-        ascii_printable_to_symbol(buf, c);
-    } else {
-        sprintf!(=> buf, "\\x%02x", 0x7f);
-    }
-    buff
-}
-
 /// Convert a wide-char to a symbol that can be used in our output.
-pub(crate) fn char_to_symbol(c: char) -> WString {
+pub fn char_to_symbol(c: char) -> WString {
     let mut buff = WString::new();
     let buf = &mut buff;
     if c <= ' ' {
         ctrl_to_symbol(buf, c);
+    } else if c == '\u{7f}' {
+        // DEL is at the end of the ASCII range
+        sprintf!(=> buf, "\\x%02x", 0x7f);
     } else if c < '\u{80}' {
         // ASCII characters that are not control characters
         ascii_printable_to_symbol(buf, c);

tests/pexpects/fkr.py

@@ -37,6 +37,9 @@ sleep(0.020)
 send("\x1B")
 expect_str("# decoded from: \\e\r\n")
 expect_str("bind escape 'do something'\r\n")
+send("ö")
+expect_str("# decoded from: ö\r\n")
+expect_str("bind ö 'do something'\r\n")
 send("\u1234")
 expect_str("bind ሴ 'do something'\r\n")