From c4f16fe3391b3b447725c10226679a6b47b5e972 Mon Sep 17 00:00:00 2001
From: Wez Furlong <wez@wezfurlong.org>
Date: Mon, 29 Jan 2024 20:01:48 -0700
Subject: [PATCH] macos: constrain fallback to normal attributes

refs: https://github.com/wez/wezterm/issues/4808
---
 docs/changelog.md                     |  2 ++
 wezterm-font/src/locator/core_text.rs | 11 +++++++++++
 2 files changed, 13 insertions(+)

diff --git a/docs/changelog.md b/docs/changelog.md
index 065d21b1f..2ca082a15 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -25,6 +25,8 @@ As features stabilize some brief notes about them will accumulate here.
 * Not yet!
 #### New
 #### Fixed
+* macOS: fallback fonts could select thin or otherwise unspecified font
+  attributes. #4808
 
 ### 20240128-202157-1e552d76
 
diff --git a/wezterm-font/src/locator/core_text.rs b/wezterm-font/src/locator/core_text.rs
index 8879ab3c1..0c4852a01 100644
--- a/wezterm-font/src/locator/core_text.rs
+++ b/wezterm-font/src/locator/core_text.rs
@@ -162,6 +162,17 @@ impl FontLocator for CoreTextFontLocator {
                     continue;
                 }
 
+                let is_normal = font.weight() == FontWeight::REGULAR
+                    && font.stretch() == FontStretch::Normal
+                    && font.style() == FontStyle::Normal;
+                if !is_normal {
+                    // Only use normal attributed text for fallbacks,
+                    // otherwise we'll end up picking something with
+                    // undefined and undesirable attributes
+                    // <https://github.com/wez/wezterm/issues/4808>
+                    continue;
+                }
+
                 if let Ok(cov) = font.coverage_intersection(&wanted) {
                     // Explicitly check coverage because the list may not
                     // actually match the text we asked about(!)