From 59468d1bc2cf4d8c3e2911c0d204f39a6ead7bcf Mon Sep 17 00:00:00 2001
From: Isilsolme <duanhaohong@163.com>
Date: Sun, 31 May 2026 19:45:11 +0800
Subject: [PATCH] Fix language preference not persisting after app restart

Use commit() instead of apply() for String preference writes to ensure
the value is written to disk synchronously before the process is killed
during restart().

Root cause: SharedPreferences.apply() writes to memory immediately but
commits to disk asynchronously. When context.restart() calls
Process.killProcess()+exitProcess(0) immediately after writing the
language preference, the async disk write may not complete, causing the
new process to read the old value.

Closes #862

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 app/src/main/java/io/legado/app/ui/config/PrefDelegate.kt  | 5 +++--
 app/src/main/java/io/legado/app/utils/ContextExtensions.kt | 3 +++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/app/src/main/java/io/legado/app/ui/config/PrefDelegate.kt b/app/src/main/java/io/legado/app/ui/config/PrefDelegate.kt
index 495fc67d5..9dad8c6f0 100644
--- a/app/src/main/java/io/legado/app/ui/config/PrefDelegate.kt
+++ b/app/src/main/java/io/legado/app/ui/config/PrefDelegate.kt
@@ -12,11 +12,12 @@ import io.legado.app.utils.getPrefFloat
 import io.legado.app.utils.getPrefInt
 import io.legado.app.utils.getPrefLong
 import io.legado.app.utils.getPrefString
+import io.legado.app.utils.putPrefString
 import io.legado.app.utils.putPrefBoolean
 import io.legado.app.utils.putPrefFloat
 import io.legado.app.utils.putPrefInt
 import io.legado.app.utils.putPrefLong
-import io.legado.app.utils.putPrefString
+import io.legado.app.utils.putPrefStringSync
 import splitties.init.appCtx
 import kotlin.properties.ReadWriteProperty
 import kotlin.reflect.KProperty
@@ -84,7 +85,7 @@ fun <T> prefDelegate(
         override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
             if (_value.value != value) {
                 when (value) {
-                    is String? -> appCtx.putPrefString(key, value)
+                    is String? -> appCtx.putPrefStringSync(key, value)
                     is Int -> appCtx.putPrefInt(key, value)
                     is Boolean -> appCtx.putPrefBoolean(key, value)
                     is Long -> appCtx.putPrefLong(key, value)
diff --git a/app/src/main/java/io/legado/app/utils/ContextExtensions.kt b/app/src/main/java/io/legado/app/utils/ContextExtensions.kt
index 41b26c2bf..d7ddc57c1 100644
--- a/app/src/main/java/io/legado/app/utils/ContextExtensions.kt
+++ b/app/src/main/java/io/legado/app/utils/ContextExtensions.kt
@@ -223,6 +223,9 @@ fun Context.getPrefString(key: String, defValue: String? = null) =
 fun Context.putPrefString(key: String, value: String?) =
     defaultSharedPreferences.edit { putString(key, value) }
 
+fun Context.putPrefStringSync(key: String, value: String?) =
+    defaultSharedPreferences.edit(commit = true) { putString(key, value) }
+
 fun Context.getPrefStringSet(
     key: String,
     defValue: MutableSet<String>? = null,