From 8556fd8176d234df6910037c51561203c19ff149 Mon Sep 17 00:00:00 2001
From: Joscha <joscha@plugh.de>
Date: Thu, 25 Apr 2024 19:45:35 +0200
Subject: [PATCH] Fix control character width measurement

---
 CHANGELOG.md   | 3 +++
 src/widthdb.rs | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2e012aa..a01f614 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,9 @@ Procedure when bumping the version number:
 
 ## Unreleased
 
+### Fixed
+- Width measurements of ASCII control characters
+
 ## v0.2.2 - 2024-01-14
 
 ### Fixed
diff --git a/src/widthdb.rs b/src/widthdb.rs
index 7d18570..200765f 100644
--- a/src/widthdb.rs
+++ b/src/widthdb.rs
@@ -101,6 +101,15 @@ impl WidthDb {
             return Ok(());
         }
         for grapheme in self.requested.drain() {
+            if grapheme.chars().any(|c|c.is_ascii_control()){
+                // ASCII control characters like the escape character or the
+                // bell character tend to be interpreted specially by terminals.
+                // This may break width measurements. To avoid this, we just
+                // assign each control character a with of 0.
+                self.known.insert(grapheme, 0);
+                continue;
+            }
+
             out.queue(Clear(ClearType::All))?
                 .queue(MoveTo(0, 0))?
                 .queue(Print(&grapheme))?;