Fix illegal state exception during backup restore of unamed groups.

app/src/main/java/org/thoughtcrime/securesms/recipients/LiveRecipientCache.java

@@ -6,6 +6,7 @@ import android.database.Cursor;
 
 import androidx.annotation.AnyThread;
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 
 import org.signal.core.util.ThreadUtil;
 import org.signal.core.util.concurrent.SignalExecutors;
@@ -176,6 +177,28 @@ public final class LiveRecipientCache {
     return getLive(selfId).resolve();
   }
 
+  /** Can safely get self id. If used during early registration (backup), will return null as we don't know self yet. */
+  @Nullable RecipientId getSelfId() {
+    RecipientId selfId;
+
+    synchronized (localRecipientId) {
+      selfId = localRecipientId.get();
+    }
+
+    if (selfId != null) {
+      return selfId;
+    }
+
+    ACI    localAci  = SignalStore.account().getAci();
+    String localE164 = SignalStore.account().getE164();
+
+    if (localAci == null && localE164 == null) {
+      return null;
+    } else {
+      return getSelf().getId();
+    }
+  }
+
   @AnyThread
   public void warmUp() {
     if (warmedUp.getAndSet(true)) {

app/src/main/java/org/thoughtcrime/securesms/recipients/Recipient.java

@@ -489,7 +489,7 @@ public class Recipient {
 
   public @Nullable String getGroupName(@NonNull Context context) {
     if (groupId != null && Util.isEmpty(this.groupName)) {
-      RecipientId     selfId = Recipient.self().getId();
+      RecipientId     selfId = ApplicationDependencies.getRecipientCache().getSelfId();
       List<Recipient> others = participantIds.stream()
                                              .filter(id -> !id.equals(selfId))
                                              .limit(MAX_MEMBER_NAMES)