Fix DEC Special Character Set (Line drawing)

This patch resolves some mapping issues with the line drawing character
set where characters like linefeed were incorrectly mapped to their
proper character representation rather than the codepoint of their
identification glpyh.

Co-authored-by: Christian Duerr <contact@christianduerr.com>

CHANGELOG.md

@@ -36,7 +36,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Vi cursor blinking not reset when navigating in search
 - Scrolling and middle-clicking modifying the primary selection
 - Bottom gap for certain builtin box drawing characters
-- Incorrect buili-in glyphs for `U+2567` and `U+2568`
+- Incorrect built-in glyphs for `U+2567` and `U+2568`
+- Character mappings in the DEC special graphics character set (line drawing)
 
 ## 0.10.1
 

alacritty_terminal/src/ansi.rs

@@ -848,16 +848,17 @@ impl StandardCharset {
         match self {
             StandardCharset::Ascii => c,
             StandardCharset::SpecialCharacterAndLineDrawing => match c {
+                '_' => ' ',
                 '`' => '◆',
                 'a' => '▒',
-                'b' => '\t',
+                'b' => '\u{2409}', // Symbol for horizontal tabulation
-                'c' => '\u{000c}',
+                'c' => '\u{240c}', // Symbol for form feed
-                'd' => '\r',
+                'd' => '\u{240d}', // Symbol for carriage return
-                'e' => '\n',
+                'e' => '\u{240a}', // Symbol for line feed
                 'f' => '°',
                 'g' => '±',
-                'h' => '\u{2424}',
+                'h' => '\u{2424}', // Symbol for newline
-                'i' => '\u{000b}',
+                'i' => '\u{240b}', // Symbol for vertical tabulation
                 'j' => '┘',
                 'k' => '┐',
                 'l' => '┌',