Stop crashing on transient network failures during archive media streams.

core/network/src/main/java/org/signal/network/RequestResultClassification.kt

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.network
+
+import org.signal.libsignal.net.BadRequestError
+import org.signal.libsignal.net.RequestResult
+import java.io.IOException
+import org.signal.libsignal.net.toRequestResult as libsignalToRequestResult
+
+/**
+ * Classifies [this] as a [RequestResult]. Prefer this over libsignal's `Throwable.toRequestResult()`.
+ *
+ * Libsignal's classifier misses handling things like IOException and forwards them as application errors.
+ */
+inline fun <reified E : BadRequestError> Throwable.toRequestResult(): RequestResult<Nothing, E> {
+  if (this is E) {
+    return RequestResult.NonSuccess(this)
+  }
+
+  val result = libsignalToRequestResult()
+  val unclassified = (result as? RequestResult.ApplicationError)?.cause
+
+  return if (unclassified is IOException) {
+    RequestResult.RetryableNetworkError(unclassified)
+  } else {
+    result
+  }
+}

core/network/src/test/java/org/signal/network/RequestResultClassificationTest.kt

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.network
+
+import assertk.assertThat
+import assertk.assertions.isEqualTo
+import assertk.assertions.isInstanceOf
+import assertk.assertions.isSameInstanceAs
+import org.junit.Test
+import org.signal.libsignal.net.RequestResult
+import org.signal.libsignal.net.RequestUnauthorizedException
+import org.signal.libsignal.net.RetryLaterException
+import java.net.SocketException
+import java.time.Duration
+
+class RequestResultClassificationTest {
+
+  @Test
+  fun `plain IOException is retryable`() {
+    val exception = SocketException("no connection")
+
+    val result = exception.toRequestResult<RequestUnauthorizedException>()
+
+    assertThat(result).isInstanceOf(RequestResult.RetryableNetworkError::class)
+    assertThat((result as RequestResult.RetryableNetworkError).networkError).isSameInstanceAs(exception)
+  }
+
+  @Test
+  fun `non-IOException is an application error`() {
+    val exception = IllegalStateException("bug")
+
+    val result = exception.toRequestResult<RequestUnauthorizedException>()
+
+    assertThat(result).isInstanceOf(RequestResult.ApplicationError::class)
+    assertThat((result as RequestResult.ApplicationError).cause).isSameInstanceAs(exception)
+  }
+
+  @Test
+  fun `libsignal classification still wins over the IOException fallback`() {
+    val exception = RetryLaterException(Duration.ofSeconds(30))
+
+    val result = exception.toRequestResult<RequestUnauthorizedException>()
+
+    assertThat(result).isInstanceOf(RequestResult.RetryableNetworkError::class)
+    assertThat((result as RequestResult.RetryableNetworkError).retryAfter).isEqualTo(Duration.ofSeconds(30))
+  }
+
+  @Test
+  fun `expected error is a non-success even though it is an IOException`() {
+    val exception = RequestUnauthorizedException("nope")
+
+    val result = exception.toRequestResult<RequestUnauthorizedException>()
+
+    assertThat(result).isInstanceOf(RequestResult.NonSuccess::class)
+    assertThat((result as RequestResult.NonSuccess).error).isSameInstanceAs(exception)
+  }
+}

lib/network/src/main/java/org/signal/network/api/ArchiveApiV2.kt

@@ -30,7 +30,6 @@ import org.signal.libsignal.net.ServerSideErrorException
 import org.signal.libsignal.net.UnauthBackupsService
 import org.signal.libsignal.net.UnauthenticatedChatConnection
 import org.signal.libsignal.net.UploadForm
-import org.signal.libsignal.net.toRequestResult
 import org.signal.libsignal.protocol.ecc.ECPrivateKey
 import org.signal.libsignal.zkgroup.GenericServerPublicParams
 import org.signal.libsignal.zkgroup.InvalidInputException
@@ -38,6 +37,7 @@ import org.signal.libsignal.zkgroup.VerificationFailedException
 import org.signal.libsignal.zkgroup.backups.BackupAuthCredential
 import org.signal.libsignal.zkgroup.backups.BackupAuthCredentialRequestContext
 import org.signal.libsignal.zkgroup.backups.BackupAuthCredentialResponse
+import org.signal.network.toRequestResult
 import org.signal.network.websocket.WebSocketRequestMessage
 import org.signal.network.websocket.WebsocketResponse
 import org.signal.network.websocket.get