From e06ac6d33e6adb7dbd98d782723ec58e8e4eeff0 Mon Sep 17 00:00:00 2001
From: Jacob Sandlund <jacob@jacobsandlund.com>
Date: Fri, 20 Feb 2026 12:12:26 -0500
Subject: [PATCH] Force prepend to use wcwidth_standalone

---
 src/build/uucode_config.zig | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/build/uucode_config.zig b/src/build/uucode_config.zig
index 594a05366..d39d4d1e1 100644
--- a/src/build/uucode_config.zig
+++ b/src/build/uucode_config.zig
@@ -20,12 +20,17 @@ fn computeWidth(
     _ = backing;
     _ = tracking;
 
-    // This condition is to get the previous behavior of uucode's `wcwidth`,
-    // returning the width of a code point in a grapheme cluster but with the
-    // exception to treat emoji modifiers as width 2 so they can be displayed
-    // in isolation. PRs to follow will take advantage of the new uucode
-    // `wcwidth_standalone` vs `wcwidth_zero_in_grapheme` split.
-    if (data.wcwidth_zero_in_grapheme and !data.is_emoji_modifier) {
+    // This condition is needed as Ghostty currently has a singular concept for
+    // the `width` of a code point, while `uucode` splits the concept into
+    // `wcwidth_standalone` and `wcwidth_zero_in_grapheme`. The two cases where
+    // we want to use the `wcwidth_standalone` despite the code point occupying
+    // zero width in a grapheme (`wcwidth_zero_in_grapheme`) are emoji
+    // modifiers and prepend code points. For emoji modifiers we want to
+    // support displaying them in isolation as color patches, and if prepend
+    // characters were to be width 0 they would disappear from the output with
+    // Ghostty's current width 0 handling. Future work will take advantage of
+    // the new uucode `wcwidth_standalone` vs `wcwidth_zero_in_grapheme` split.
+    if (data.wcwidth_zero_in_grapheme and !data.is_emoji_modifier and data.grapheme_break_no_control != .prepend) {
         data.width = 0;
     } else {
         data.width = @min(2, data.wcwidth_standalone);
@@ -37,6 +42,7 @@ const width = config.Extension{
         "wcwidth_standalone",
         "wcwidth_zero_in_grapheme",
         "is_emoji_modifier",
+        "grapheme_break_no_control",
     },
     .compute = &computeWidth,
     .fields = &.{