Support gv2 avatar removal.

app/src/main/java/org/thoughtcrime/securesms/groups/GroupManager.java

@@ -73,7 +73,7 @@ public final class GroupManager {
   {
     if (groupId.isV2()) {
       try (GroupManagerV2.GroupEditor edit = new GroupManagerV2(context).edit(groupId.requireV2())) {
-        return edit.updateGroupTitleAndAvatar(name, avatarChanged ? avatar : null);
+        return edit.updateGroupTitleAndAvatar(name, avatar, avatarChanged);
       }
     } else {
       List<Recipient> members = DatabaseFactory.getGroupDatabase(context)

app/src/main/java/org/thoughtcrime/securesms/groups/GroupManagerV2.java

@@ -209,23 +209,24 @@ final class GroupManagerV2 {
     }
 
     @WorkerThread
-    @NonNull GroupManager.GroupActionResult updateGroupTitleAndAvatar(@Nullable String title, @Nullable byte[] avatarBytes)
+    @NonNull GroupManager.GroupActionResult updateGroupTitleAndAvatar(@Nullable String title, @Nullable byte[] avatarBytes, boolean avatarChanged)
       throws GroupChangeFailedException, GroupInsufficientRightsException, IOException, GroupNotAMemberException
     {
       try {
         GroupChange.Actions.Builder change = groupOperations.createModifyGroupTitleAndMembershipChange(Optional.fromNullable(title), Collections.emptySet(), Collections.emptySet());
 
-        if (avatarBytes != null) {
+        if (avatarChanged) {
-          String cdnKey = groupsV2Api.uploadAvatar(avatarBytes, groupSecretParams, authorization.getAuthorizationForToday(selfUuid, groupSecretParams));
+          String cdnKey = avatarBytes != null ? groupsV2Api.uploadAvatar(avatarBytes, groupSecretParams, authorization.getAuthorizationForToday(selfUuid, groupSecretParams))
+                                              : "";
           change.setModifyAvatar(GroupChange.Actions.ModifyAvatarAction.newBuilder()
-                                                                       .setAvatar(cdnKey));
+                                                    .setAvatar(cdnKey));
         }
 
         GroupManager.GroupActionResult groupActionResult = commitChangeWithConflictResolution(change);
 
-        if (avatarBytes != null) {
+        if (avatarChanged) {
-          AvatarHelper.setAvatar(context, Recipient.externalGroup(context, groupId).getId(), new ByteArrayInputStream(avatarBytes));
+          AvatarHelper.setAvatar(context, Recipient.externalGroup(context, groupId).getId(), avatarBytes != null ? new ByteArrayInputStream(avatarBytes) : null);
-          groupDatabase.onAvatarUpdated(groupId, true);
+          groupDatabase.onAvatarUpdated(groupId, avatarBytes != null);
         }
 
         return groupActionResult;

app/src/main/java/org/thoughtcrime/securesms/groups/v2/processing/GroupsV2StateProcessor.java

@@ -1,6 +1,7 @@
 package org.thoughtcrime.securesms.groups.v2.processing;
 
 import android.content.Context;
+import android.text.TextUtils;
 
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
@@ -11,7 +12,6 @@ import org.signal.storageservice.protos.groups.local.DecryptedGroupChange;
 import org.signal.zkgroup.VerificationFailedException;
 import org.signal.zkgroup.groups.GroupMasterKey;
 import org.signal.zkgroup.groups.GroupSecretParams;
-import org.signal.zkgroup.util.UUIDUtil;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.GroupDatabase;
 import org.thoughtcrime.securesms.database.MmsDatabase;
@@ -223,15 +223,18 @@ public final class GroupsV2StateProcessor {
     private void updateLocalDatabaseGroupState(@NonNull GlobalGroupState inputGroupState,
                                                @NonNull DecryptedGroup newLocalState)
     {
+      boolean needsAvatarFetch;
+
       if (inputGroupState.getLocalState() == null) {
         groupDatabase.create(masterKey, newLocalState);
+        needsAvatarFetch = !TextUtils.isEmpty(newLocalState.getAvatar());
       } else {
         groupDatabase.update(masterKey, newLocalState);
+        needsAvatarFetch = !newLocalState.getAvatar().equals(inputGroupState.getLocalState().getAvatar());
       }
 
-      String avatar = newLocalState.getAvatar();
+      if (needsAvatarFetch) {
-      if (!avatar.isEmpty()) {
+        jobManager.add(new AvatarGroupsV2DownloadJob(groupId, newLocalState.getAvatar()));
-        jobManager.add(new AvatarGroupsV2DownloadJob(groupId, avatar));
       }
 
       final boolean fullMemberPostUpdate = GroupProtoUtil.isMember(Recipient.self().getUuid().get(), newLocalState.getMembersList());

app/src/main/java/org/thoughtcrime/securesms/jobs/AvatarGroupsV2DownloadJob.java

@@ -46,14 +46,7 @@ public final class AvatarGroupsV2DownloadJob extends BaseJob {
                        .setMaxAttempts(10)
                        .build(),
          groupId,
-         requireNonEmpty(cdnKey));
+         cdnKey);
-  }
-
-  private static String requireNonEmpty(@NonNull String string) {
-    if (string.isEmpty()) {
-      throw new AssertionError();
-    }
-    return string;
   }
 
   private AvatarGroupsV2DownloadJob(@NonNull Parameters parameters, @NonNull GroupId.V2 groupId, @NonNull String cdnKey) {
@@ -87,6 +80,15 @@ public final class AvatarGroupsV2DownloadJob extends BaseJob {
         return;
       }
 
+      if (cdnKey.length() == 0) {
+        Log.w(TAG, "Removing avatar for group " + groupId);
+        AvatarHelper.setAvatar(context, record.get().getRecipientId(), null);
+        database.onAvatarUpdated(groupId, false);
+        return;
+      }
+
+      Log.i(TAG, "Downloading new avatar for group " + groupId);
+
       attachment = File.createTempFile("avatar", "gv2", context.getCacheDir());
       attachment.deleteOnExit();
 

app/src/main/java/org/thoughtcrime/securesms/profiles/edit/EditProfileViewModel.java

@@ -90,7 +90,7 @@ class EditProfileViewModel extends ViewModel {
   }
 
   public boolean canRemoveProfilePhoto() {
-    return (!isGroup() || groupId.isV1()) && hasAvatar();
+    return hasAvatar();
   }
 
   @MainThread