From ab84a02152b7f9d4e7bfbe4555bda0b2550e32ac Mon Sep 17 00:00:00 2001
From: Lawrence Chen <54008264+lawrencecchen@users.noreply.github.com>
Date: Fri, 20 Feb 2026 14:30:21 -0800
Subject: [PATCH] Fix reload config to honor legacy Ghostty config fallback
 (#202)

---
 Sources/GhosttyTerminalView.swift  | 31 +++++++++++++++++--------
 cmuxTests/GhosttyConfigTests.swift | 36 ++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+), 9 deletions(-)

diff --git a/Sources/GhosttyTerminalView.swift b/Sources/GhosttyTerminalView.swift
index fb23ab7f..7bc8194f 100644
--- a/Sources/GhosttyTerminalView.swift
+++ b/Sources/GhosttyTerminalView.swift
@@ -288,9 +288,7 @@ class GhosttyApp {
 
         // Load default config (includes user config). If this fails hard (e.g. due to
         // invalid user config), ghostty_app_new may return nil; we fall back below.
-        ghostty_config_load_default_files(primaryConfig)
-        loadLegacyGhosttyConfigIfNeeded(primaryConfig)
-        ghostty_config_finalize(primaryConfig)
+        loadDefaultConfigFilesWithLegacyFallback(primaryConfig)
         updateDefaultBackground(from: primaryConfig)
 
         // Create runtime config with callbacks
@@ -458,6 +456,21 @@ class GhosttyApp {
         #endif
     }
 
+    private func loadDefaultConfigFilesWithLegacyFallback(_ config: ghostty_config_t) {
+        ghostty_config_load_default_files(config)
+        loadLegacyGhosttyConfigIfNeeded(config)
+        ghostty_config_finalize(config)
+    }
+
+    static func shouldLoadLegacyGhosttyConfig(
+        newConfigFileSize: Int?,
+        legacyConfigFileSize: Int?
+    ) -> Bool {
+        guard let newConfigFileSize, newConfigFileSize == 0 else { return false }
+        guard let legacyConfigFileSize, legacyConfigFileSize > 0 else { return false }
+        return true
+    }
+
     private func loadLegacyGhosttyConfigIfNeeded(_ config: ghostty_config_t) {
         #if os(macOS)
         // Ghostty 1.3+ prefers `config.ghostty`, but some users still have their real
@@ -475,8 +488,10 @@ class GhosttyApp {
             return size.intValue
         }
 
-        guard let newSize = fileSize(configNew), newSize == 0 else { return }
-        guard let legacySize = fileSize(configLegacy), legacySize > 0 else { return }
+        guard Self.shouldLoadLegacyGhosttyConfig(
+            newConfigFileSize: fileSize(configNew),
+            legacyConfigFileSize: fileSize(configLegacy)
+        ) else { return }
 
         configLegacy.path.withCString { path in
             ghostty_config_load_file(config, path)
@@ -512,8 +527,7 @@ class GhosttyApp {
         }
 
         guard let newConfig = ghostty_config_new() else { return }
-        ghostty_config_load_default_files(newConfig)
-        ghostty_config_finalize(newConfig)
+        loadDefaultConfigFilesWithLegacyFallback(newConfig)
         ghostty_app_update_config(app, newConfig)
         updateDefaultBackground(from: newConfig)
         DispatchQueue.main.async {
@@ -533,8 +547,7 @@ class GhosttyApp {
         }
 
         guard let newConfig = ghostty_config_new() else { return }
-        ghostty_config_load_default_files(newConfig)
-        ghostty_config_finalize(newConfig)
+        loadDefaultConfigFilesWithLegacyFallback(newConfig)
         ghostty_surface_update_config(surface, newConfig)
         ghostty_config_free(newConfig)
     }
diff --git a/cmuxTests/GhosttyConfigTests.swift b/cmuxTests/GhosttyConfigTests.swift
index b6f13d4d..dddecf16 100644
--- a/cmuxTests/GhosttyConfigTests.swift
+++ b/cmuxTests/GhosttyConfigTests.swift
@@ -126,6 +126,42 @@ final class GhosttyConfigTests: XCTestCase {
         XCTAssertEqual(rgb255(config.backgroundColor), RGB(red: 253, green: 246, blue: 227))
     }
 
+    func testLegacyConfigFallbackUsesLegacyFileWhenConfigGhosttyIsEmpty() {
+        XCTAssertTrue(
+            GhosttyApp.shouldLoadLegacyGhosttyConfig(
+                newConfigFileSize: 0,
+                legacyConfigFileSize: 42
+            )
+        )
+    }
+
+    func testLegacyConfigFallbackSkipsWhenNewFileMissingOrLegacyEmpty() {
+        XCTAssertFalse(
+            GhosttyApp.shouldLoadLegacyGhosttyConfig(
+                newConfigFileSize: nil,
+                legacyConfigFileSize: 42
+            )
+        )
+        XCTAssertFalse(
+            GhosttyApp.shouldLoadLegacyGhosttyConfig(
+                newConfigFileSize: 10,
+                legacyConfigFileSize: 42
+            )
+        )
+        XCTAssertFalse(
+            GhosttyApp.shouldLoadLegacyGhosttyConfig(
+                newConfigFileSize: 0,
+                legacyConfigFileSize: 0
+            )
+        )
+        XCTAssertFalse(
+            GhosttyApp.shouldLoadLegacyGhosttyConfig(
+                newConfigFileSize: 0,
+                legacyConfigFileSize: nil
+            )
+        )
+    }
+
     private func rgb255(_ color: NSColor) -> RGB {
         let srgb = color.usingColorSpace(.sRGB)!
         var red: CGFloat = 0