diff --git a/tools/chatgui-android/language-tests/src/main/kotlin/android/content/Context.kt b/tools/chatgui-android/language-tests/src/main/kotlin/android/content/Context.kt
index 1e538f35..ee5af5d4 100644
--- a/tools/chatgui-android/language-tests/src/main/kotlin/android/content/Context.kt
+++ b/tools/chatgui-android/language-tests/src/main/kotlin/android/content/Context.kt
@@ -20,7 +20,9 @@ class Context {
 }
 
 class HostResources {
-    val configuration = HostConfiguration()
+    private val current = HostConfiguration()
+    var failConfiguration = false
+    val configuration: HostConfiguration get() { check(!failConfiguration) { "configuration unavailable" }; return current }
     var xml: String? = null
     var failOpen = false
     var failNext = false
diff --git a/tools/chatgui-android/language-tests/src/test/kotlin/com/utun/chat/data/AppLanguageRefreshTest.kt b/tools/chatgui-android/language-tests/src/test/kotlin/com/utun/chat/data/AppLanguageRefreshTest.kt
new file mode 100644
index 00000000..12bcf45f
--- /dev/null
+++ b/tools/chatgui-android/language-tests/src/test/kotlin/com/utun/chat/data/AppLanguageRefreshTest.kt
@@ -0,0 +1,97 @@
+package com.utun.chat.data
+
+import android.content.Context
+import android.os.Looper
+import androidx.appcompat.app.AppCompatDelegate
+import androidx.core.content.ContextCompat
+import androidx.core.os.LocaleListCompat
+import com.utun.chat.ChatApplication
+import java.util.concurrent.atomic.AtomicReference
+import org.junit.Assert.*
+import org.junit.Before
+import org.junit.Test
+
+/** Реальный applied(); владельцы уведомлений считают независимые попытки, не запускают службы/медиа. */
+class AppLanguageRefreshTest {
+    private val owners = listOf("network", "incoming call", "ongoing call", "radio")
+    private lateinit var context: Context
+    companion object { private var sequence = 0 }
+
+    @Before fun prepare() {
+        assertSame(Looper.getMainLooper(), Looper.myLooper())
+        context = Context(); ChatApplication.instance = context
+        context.resources.configuration.locales = LocaleListCompat.forLanguageTags("en-x-test-${++sequence}")
+        ContextCompat.failContext = false
+        AppCompatDelegate.failRead = false; AppCompatDelegate.failWrite = false
+        AppCompatDelegate.requested = LocaleListCompat.forLanguageTags("ru")
+        AppCompatDelegate.selections.clear()
+        HostLanguageNotifications.attempts.clear(); HostLanguageNotifications.failures.clear()
+        LogManager.entries.clear()
+    }
+
+    @Test fun dispatchesAllOwnersUsingEffectiveResourcesWithoutChangingSelection() {
+        AppLanguage.applied()
+        assertEquals(owners, HostLanguageNotifications.attempts)
+        assertTrue(AppCompatDelegate.selections.isEmpty())
+        assertEquals("ru", AppCompatDelegate.requested.toLanguageTags())
+        val effective = context.resources.configuration.locales.toLanguageTags()
+        assertTrue(LogManager.entries.any { effective in it.message })
+    }
+
+    @Test fun everyFailedOwnerCanBeRetriedWithTheSameLocales() {
+        for ((index, owner) in owners.withIndex()) {
+            context.resources.configuration.locales = LocaleListCompat.forLanguageTags("en-x-retry-${sequence}-$index")
+            HostLanguageNotifications.failures.add(owner)
+            HostLanguageNotifications.attempts.clear()
+            AppLanguage.applied()
+            assertEquals(owners, HostLanguageNotifications.attempts)
+            assertTrue(LogManager.entries.any { it.level == "ERROR" && owner in it.message })
+            HostLanguageNotifications.failures.clear(); HostLanguageNotifications.attempts.clear()
+            AppLanguage.applied()
+            assertEquals("owner=$owner", owners, HostLanguageNotifications.attempts)
+        }
+    }
+
+    @Test fun sameLocalesStillReachOwnersThatFailedInternallyOrBecameActiveLater() {
+        AppLanguage.applied()
+        HostLanguageNotifications.attempts.clear()
+        AppLanguage.applied()
+        assertEquals(owners, HostLanguageNotifications.attempts)
+    }
+
+    @Test fun allOwnerFailuresAreIsolatedAndLogged() {
+        HostLanguageNotifications.failures.addAll(owners)
+        assertNull(runCatching { AppLanguage.applied() }.exceptionOrNull())
+        assertEquals(owners, HostLanguageNotifications.attempts)
+        assertEquals(4, LogManager.entries.count { it.level == "ERROR" && "notification" in it.message.lowercase() })
+    }
+
+    @Test fun contextFailureIsReportedWithoutEscapingConfigurationCallback() {
+        ContextCompat.failContext = true
+        assertNull(runCatching { AppLanguage.applied() }.exceptionOrNull())
+        assertTrue(HostLanguageNotifications.attempts.isEmpty())
+        assertTrue(LogManager.entries.any { it.level == "ERROR" && "context unavailable" in it.message })
+        ContextCompat.failContext = false
+        AppLanguage.applied()
+        assertEquals(owners, HostLanguageNotifications.attempts)
+    }
+
+    @Test fun configurationFailureDoesNotPoisonTheNextSignal() {
+        context.resources.failConfiguration = true
+        assertNull(runCatching { AppLanguage.applied() }.exceptionOrNull())
+        assertTrue(HostLanguageNotifications.attempts.isEmpty())
+        assertTrue(LogManager.entries.any { it.level == "ERROR" && "configuration unavailable" in it.message })
+        context.resources.failConfiguration = false
+        AppLanguage.applied()
+        assertEquals(owners, HostLanguageNotifications.attempts)
+    }
+
+    @Test fun backgroundSignalIsRejectedBeforeCallingAnyOwner() {
+        val failure = AtomicReference<Throwable?>()
+        val worker = Thread { failure.set(runCatching { AppLanguage.applied() }.exceptionOrNull()) }.apply { start() }
+        worker.join(2000); assertFalse(worker.isAlive)
+        assertTrue(failure.get() is IllegalStateException)
+        assertTrue(HostLanguageNotifications.attempts.isEmpty())
+        assertTrue(LogManager.entries.any { it.level == "ERROR" && "main thread" in it.message })
+    }
+}