From e8616c342d1e33e8c935dd88a824657a2362578a Mon Sep 17 00:00:00 2001
From: Shreesh Ayachit <shreesha@meta.com>
Date: Mon, 28 Sep 2026 11:24:56 -0700
Subject: [PATCH] Use ConfigurationCompat for device locale lookup

Summary:
`I18nUtil` directly called `Configuration.getLocales()`, which is unavailable before API 24. Read the preferred locale through `ConfigurationCompat` instead and fall back to the process default when the locale list is empty.

Add an API-23 Robolectric regression test that exercises RTL detection on an Arabic locale.

Changelog:
[Android][Fixed] - Prevent a crash when resolving RTL layout direction on Android 6

Reviewed By: cortinico

Differential Revision: D122147089
---
 .../react/modules/i18nmanager/I18nUtil.kt     |  7 +++-
 .../react/modules/i18nmanager/I18nUtilTest.kt | 38 +++++++++++++++++++
 2 files changed, 43 insertions(+), 2 deletions(-)
 create mode 100644 packages/react-native/ReactAndroid/src/test/java/com/facebook/react/modules/i18nmanager/I18nUtilTest.kt

diff --git a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/i18nmanager/I18nUtil.kt b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/i18nmanager/I18nUtil.kt
index 3177d0efe3d..b991a34bdcf 100644
--- a/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/i18nmanager/I18nUtil.kt
+++ b/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/modules/i18nmanager/I18nUtil.kt
@@ -10,7 +10,9 @@ package com.facebook.react.modules.i18nmanager
 import android.content.Context
 import android.content.pm.ApplicationInfo
 import android.view.View
+import androidx.core.os.ConfigurationCompat
 import androidx.core.text.TextUtilsCompat
+import java.util.Locale
 
 public class I18nUtil private constructor() {
   /**
@@ -61,8 +63,9 @@ public class I18nUtil private constructor() {
 
   // Check if the current device language is RTL
   private fun isDevicePreferredLanguageRTL(context: Context): Boolean {
-    val directionality =
-        TextUtilsCompat.getLayoutDirectionFromLocale(context.resources.configuration.locales[0])
+    val locale =
+        ConfigurationCompat.getLocales(context.resources.configuration)[0] ?: Locale.getDefault()
+    val directionality = TextUtilsCompat.getLayoutDirectionFromLocale(locale)
     return directionality == View.LAYOUT_DIRECTION_RTL
   }
 
diff --git a/packages/react-native/ReactAndroid/src/test/java/com/facebook/react/modules/i18nmanager/I18nUtilTest.kt b/packages/react-native/ReactAndroid/src/test/java/com/facebook/react/modules/i18nmanager/I18nUtilTest.kt
new file mode 100644
index 00000000000..cee9e18a989
--- /dev/null
+++ b/packages/react-native/ReactAndroid/src/test/java/com/facebook/react/modules/i18nmanager/I18nUtilTest.kt
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+package com.facebook.react.modules.i18nmanager
+
+import android.content.Context
+import android.content.pm.ApplicationInfo
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.RuntimeEnvironment
+import org.robolectric.annotation.Config
+
+@RunWith(RobolectricTestRunner::class)
+internal class I18nUtilTest {
+  private lateinit var context: Context
+
+  @Before
+  fun setUp() {
+    context = RuntimeEnvironment.getApplication()
+    context.applicationInfo.flags =
+        context.applicationInfo.flags or ApplicationInfo.FLAG_SUPPORTS_RTL
+    I18nUtil.instance.allowRTL(context, true)
+    I18nUtil.instance.forceRTL(context, false)
+  }
+
+  @Test
+  @Config(sdk = [23], qualifiers = "ar")
+  fun isRTL_onApi23_usesPreferredLocale() {
+    assertThat(I18nUtil.instance.isRTL(context)).isTrue()
+  }
+}