Write previous group state to the database for advanced change messages.

app/src/main/java/org/thoughtcrime/securesms/database/model/GroupsV2UpdateMessageProducer.java

@@ -3,6 +3,7 @@ package org.thoughtcrime.securesms.database.model;
 import android.content.Context;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.annotation.WorkerThread;
 
 import com.google.protobuf.ByteString;
@@ -81,7 +82,11 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
-  List<UpdateDescription> describeChanges(@NonNull DecryptedGroupChange change) {
+  List<UpdateDescription> describeChanges(@Nullable DecryptedGroup previousGroupState, @NonNull DecryptedGroupChange change) {
+    if (DecryptedGroup.getDefaultInstance().equals(previousGroupState)) {
+      previousGroupState = null;
+    }
+
     List<UpdateDescription> updates = new LinkedList<>();
 
     if (change.getEditor().isEmpty() || UuidUtil.UNKNOWN_UUID.equals(UuidUtil.fromByteString(change.getEditor()))) {
@@ -96,7 +101,7 @@ final class GroupsV2UpdateMessageProducer {
       describeUnknownEditorNewTimer(change, updates);
       describeUnknownEditorNewAttributeAccess(change, updates);
       describeUnknownEditorNewMembershipAccess(change, updates);
-      describeUnknownEditorNewGroupInviteLinkAccess(change, updates);
+      describeUnknownEditorNewGroupInviteLinkAccess(previousGroupState, change, updates);
       describeRequestingMembers(change, updates);
       describeUnknownEditorRequestingMembersApprovals(change, updates);
       describeUnknownEditorRequestingMembersDeletes(change, updates);
@@ -119,7 +124,7 @@ final class GroupsV2UpdateMessageProducer {
       describeNewTimer(change, updates);
       describeNewAttributeAccess(change, updates);
       describeNewMembershipAccess(change, updates);
-      describeNewGroupInviteLinkAccess(change, updates);
+      describeNewGroupInviteLinkAccess(previousGroupState, change, updates);
       describeRequestingMembers(change, updates);
       describeRequestingMembersApprovals(change, updates);
       describeRequestingMembersDeletes(change, updates);
@@ -509,7 +514,16 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
-  private void describeNewGroupInviteLinkAccess(@NonNull DecryptedGroupChange change, @NonNull List<UpdateDescription> updates) {
+  private void describeNewGroupInviteLinkAccess(@Nullable DecryptedGroup previousGroupState,
+                                                @NonNull DecryptedGroupChange change,
+                                                @NonNull List<UpdateDescription> updates)
+  {
+    AccessControl.AccessRequired previousAccessControl = null;
+
+    if (previousGroupState != null) {
+      previousAccessControl = previousGroupState.getAccessControl().getAddFromInviteLink();
+    }
+
     boolean editorIsYou      = change.getEditor().equals(selfUuidBytes);
     boolean groupLinkEnabled = false;
 
@@ -517,17 +531,33 @@ final class GroupsV2UpdateMessageProducer {
       case ANY:
         groupLinkEnabled = true;
         if (editorIsYou) {
-          updates.add(updateDescription(context.getString(R.string.MessageRecord_you_turned_on_the_group_link_with_admin_approval_off)));
+          if (previousAccessControl == AccessControl.AccessRequired.ADMINISTRATOR) {
+            updates.add(updateDescription(context.getString(R.string.MessageRecord_you_turned_off_admin_approval_for_the_group_link)));
+          } else {
+            updates.add(updateDescription(context.getString(R.string.MessageRecord_you_turned_on_the_group_link_with_admin_approval_off)));
+          }
         } else {
-          updates.add(updateDescription(change.getEditor(), editor -> context.getString(R.string.MessageRecord_s_turned_on_the_group_link_with_admin_approval_off, editor)));
+          if (previousAccessControl == AccessControl.AccessRequired.ADMINISTRATOR) {
+            updates.add(updateDescription(change.getEditor(), editor -> context.getString(R.string.MessageRecord_s_turned_off_admin_approval_for_the_group_link, editor)));
+          } else {
+            updates.add(updateDescription(change.getEditor(), editor -> context.getString(R.string.MessageRecord_s_turned_on_the_group_link_with_admin_approval_off, editor)));
+          }
         }
         break;
       case ADMINISTRATOR:
         groupLinkEnabled = true;
         if (editorIsYou) {
-          updates.add(updateDescription(context.getString(R.string.MessageRecord_you_turned_on_the_group_link_with_admin_approval_on)));
+          if (previousAccessControl == AccessControl.AccessRequired.ANY) {
+            updates.add(updateDescription(context.getString(R.string.MessageRecord_you_turned_on_admin_approval_for_the_group_link)));
+          } else {
+            updates.add(updateDescription(context.getString(R.string.MessageRecord_you_turned_on_the_group_link_with_admin_approval_on)));
+          }
         } else {
-          updates.add(updateDescription(change.getEditor(), editor -> context.getString(R.string.MessageRecord_s_turned_on_the_group_link_with_admin_approval_on, editor)));
+          if (previousAccessControl == AccessControl.AccessRequired.ANY) {
+            updates.add(updateDescription(change.getEditor(), editor -> context.getString(R.string.MessageRecord_s_turned_on_admin_approval_for_the_group_link, editor)));
+          } else {
+            updates.add(updateDescription(change.getEditor(), editor -> context.getString(R.string.MessageRecord_s_turned_on_the_group_link_with_admin_approval_on, editor)));
+          }
         }
         break;
       case UNSATISFIABLE:
@@ -548,13 +578,30 @@ final class GroupsV2UpdateMessageProducer {
     }
   }
 
-  private void describeUnknownEditorNewGroupInviteLinkAccess(@NonNull DecryptedGroupChange change, @NonNull List<UpdateDescription> updates) {
+  private void describeUnknownEditorNewGroupInviteLinkAccess(@Nullable DecryptedGroup previousGroupState,
+                                                             @NonNull DecryptedGroupChange change,
+                                                             @NonNull List<UpdateDescription> updates)
+  {
+    AccessControl.AccessRequired previousAccessControl = null;
+
+    if (previousGroupState != null) {
+      previousAccessControl = previousGroupState.getAccessControl().getAddFromInviteLink();
+    }
+
     switch (change.getNewInviteLinkAccess()) {
       case ANY:
-        updates.add(updateDescription(context.getString(R.string.MessageRecord_the_group_link_has_been_turned_on_with_admin_approval_off)));
+        if (previousAccessControl == AccessControl.AccessRequired.ADMINISTRATOR) {
+          updates.add(updateDescription(context.getString(R.string.MessageRecord_the_admin_approval_for_the_group_link_has_been_turned_off)));
+        } else {
+          updates.add(updateDescription(context.getString(R.string.MessageRecord_the_group_link_has_been_turned_on_with_admin_approval_off)));
+        }
         break;
       case ADMINISTRATOR:
-        updates.add(updateDescription(context.getString(R.string.MessageRecord_the_group_link_has_been_turned_on_with_admin_approval_on)));
+        if (previousAccessControl == AccessControl.AccessRequired.ANY) {
+          updates.add(updateDescription(context.getString(R.string.MessageRecord_the_admin_approval_for_the_group_link_has_been_turned_on)));
+        } else {
+          updates.add(updateDescription(context.getString(R.string.MessageRecord_the_group_link_has_been_turned_on_with_admin_approval_on)));
+        }
         break;
       case UNSATISFIABLE:
         updates.add(updateDescription(context.getString(R.string.MessageRecord_the_group_link_has_been_turned_off)));

app/src/main/java/org/thoughtcrime/securesms/database/model/MessageRecord.java

@@ -177,7 +177,7 @@ public abstract class MessageRecord extends DisplayRecord {
       GroupsV2UpdateMessageProducer  updateMessageProducer   = new GroupsV2UpdateMessageProducer(context, descriptionStrategy, Recipient.self().getUuid().get());
 
       if (decryptedGroupV2Context.hasChange() && decryptedGroupV2Context.getGroupState().getRevision() != 0) {
-        return UpdateDescription.concatWithNewLines(updateMessageProducer.describeChanges(decryptedGroupV2Context.getChange()));
+        return UpdateDescription.concatWithNewLines(updateMessageProducer.describeChanges(decryptedGroupV2Context.getPreviousGroupState(), decryptedGroupV2Context.getChange()));
       } else {
         return updateMessageProducer.describeNewGroup(decryptedGroupV2Context.getGroupState(), decryptedGroupV2Context.getChange());
       }

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

@@ -193,7 +193,7 @@ final class GroupManagerV2 {
                                                                .setEditor(UuidUtil.toByteString(selfUuid))
                                                                .build();
 
-        RecipientAndThread recipientAndThread = sendGroupUpdate(masterKey, decryptedGroup, groupChange, null);
+        RecipientAndThread recipientAndThread = sendGroupUpdate(masterKey, new GroupMutation(null, groupChange, decryptedGroup), null);
 
         return new GroupManager.GroupActionResult(recipientAndThread.groupRecipient,
                                                   recipientAndThread.threadId,
@@ -505,16 +505,18 @@ final class GroupManagerV2 {
     private GroupManager.GroupActionResult commitChange(@NonNull GroupChange.Actions.Builder change)
         throws GroupNotAMemberException, GroupChangeFailedException, IOException, GroupInsufficientRightsException
     {
-      final GroupDatabase.GroupRecord       groupRecord       = groupDatabase.requireGroup(groupId);
+      final GroupDatabase.GroupRecord       groupRecord         = groupDatabase.requireGroup(groupId);
-      final GroupDatabase.V2GroupProperties v2GroupProperties = groupRecord.requireV2GroupProperties();
+      final GroupDatabase.V2GroupProperties v2GroupProperties   = groupRecord.requireV2GroupProperties();
-      final int                             nextRevision      = v2GroupProperties.getGroupRevision() + 1;
+      final int                             nextRevision        = v2GroupProperties.getGroupRevision() + 1;
-      final GroupChange.Actions             changeActions     = change.setRevision(nextRevision).build();
+      final GroupChange.Actions             changeActions       = change.setRevision(nextRevision).build();
       final DecryptedGroupChange            decryptedChange;
       final DecryptedGroup                  decryptedGroupState;
+      final DecryptedGroup                  previousGroupState;
 
       try {
+        previousGroupState  = v2GroupProperties.getDecryptedGroup();
         decryptedChange     = groupOperations.decryptChange(changeActions, selfUuid);
-        decryptedGroupState = DecryptedGroupUtil.apply(v2GroupProperties.getDecryptedGroup(), decryptedChange);
+        decryptedGroupState = DecryptedGroupUtil.apply(previousGroupState, decryptedChange);
       } catch (VerificationFailedException | InvalidGroupStateException | NotAbleToApplyGroupV2ChangeException e) {
         Log.w(TAG, e);
         throw new IOException(e);
@@ -523,7 +525,8 @@ final class GroupManagerV2 {
       GroupChange signedGroupChange = commitToServer(changeActions);
       groupDatabase.update(groupId, decryptedGroupState);
 
-      RecipientAndThread recipientAndThread = sendGroupUpdate(groupMasterKey, decryptedGroupState, decryptedChange, signedGroupChange);
+      GroupMutation      groupMutation      = new GroupMutation(previousGroupState, decryptedChange, decryptedGroupState);
+      RecipientAndThread recipientAndThread = sendGroupUpdate(groupMasterKey, groupMutation, signedGroupChange);
       int                newMembersCount    = decryptedChange.getNewMembersCount();
       List<RecipientId>  newPendingMembers  = getPendingMemberRecipientIds(decryptedChange.getNewPendingMembersList());
 
@@ -681,7 +684,7 @@ final class GroupManagerV2 {
       } else if (requestToJoin) {
         Log.i(TAG, "Requested to join, cannot send update");
 
-        RecipientAndThread recipientAndThread = sendGroupUpdate(groupMasterKey, decryptedGroup, decryptedChange, signedGroupChange);
+        RecipientAndThread recipientAndThread = sendGroupUpdate(groupMasterKey, new GroupMutation(null, decryptedChange, decryptedGroup), signedGroupChange);
 
         return new GroupManager.GroupActionResult(groupRecipient,
                                                   recipientAndThread.threadId,
@@ -706,7 +709,7 @@ final class GroupManagerV2 {
                                                                        System.currentTimeMillis(),
                                                                        decryptedChange);
 
-        RecipientAndThread recipientAndThread = sendGroupUpdate(groupMasterKey, decryptedGroup, decryptedChange, signedGroupChange);
+        RecipientAndThread recipientAndThread = sendGroupUpdate(groupMasterKey, new GroupMutation(null, decryptedChange, decryptedGroup), signedGroupChange);
 
         return new GroupManager.GroupActionResult(groupRecipient,
                                                   recipientAndThread.threadId,
@@ -905,7 +908,7 @@ final class GroupManagerV2 {
 
         groupDatabase.update(groupId, resetRevision(newGroup, decryptedGroup.getRevision()));
 
-        sendGroupUpdate(groupMasterKey, decryptedGroup, decryptedChange, signedGroupChange);
+        sendGroupUpdate(groupMasterKey, new GroupMutation(decryptedGroup, decryptedChange, newGroup), signedGroupChange);
       } catch (VerificationFailedException | InvalidGroupStateException | NotAbleToApplyGroupV2ChangeException e) {
         throw new GroupChangeFailedException(e);
       }
@@ -959,13 +962,12 @@ final class GroupManagerV2 {
   }
 
   private @NonNull RecipientAndThread sendGroupUpdate(@NonNull GroupMasterKey masterKey,
-                                                      @NonNull DecryptedGroup decryptedGroup,
+                                                      @NonNull GroupMutation groupMutation,
-                                                      @Nullable DecryptedGroupChange plainGroupChange,
                                                       @Nullable GroupChange signedGroupChange)
   {
     GroupId.V2                groupId                 = GroupId.v2(masterKey);
     Recipient                 groupRecipient          = Recipient.externalGroup(context, groupId);
-    DecryptedGroupV2Context   decryptedGroupV2Context = GroupProtoUtil.createDecryptedGroupV2Context(masterKey, decryptedGroup, plainGroupChange, signedGroupChange);
+    DecryptedGroupV2Context   decryptedGroupV2Context = GroupProtoUtil.createDecryptedGroupV2Context(masterKey, groupMutation, signedGroupChange);
     OutgoingGroupUpdateMessage outgoingMessage        = new OutgoingGroupUpdateMessage(groupRecipient,
                                                                                        decryptedGroupV2Context,
                                                                                        null,
@@ -977,8 +979,11 @@ final class GroupManagerV2 {
                                                                                        Collections.emptyList(),
                                                                                        Collections.emptyList());
 
+
+    DecryptedGroupChange plainGroupChange = groupMutation.getGroupChange();
+
     if (plainGroupChange != null && DecryptedGroupUtil.changeIsEmptyExceptForProfileKeyChanges(plainGroupChange)) {
-      ApplicationDependencies.getJobManager().add(PushGroupSilentUpdateSendJob.create(context, groupId, decryptedGroup, outgoingMessage));
+      ApplicationDependencies.getJobManager().add(PushGroupSilentUpdateSendJob.create(context, groupId, groupMutation.getNewGroupState(), outgoingMessage));
       return new RecipientAndThread(groupRecipient, -1);
     } else {
       long threadId = MessageSender.send(context, outgoingMessage, -1, false, null);

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

@@ -0,0 +1,31 @@
+package org.thoughtcrime.securesms.groups;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import org.signal.storageservice.protos.groups.local.DecryptedGroup;
+import org.signal.storageservice.protos.groups.local.DecryptedGroupChange;
+
+public final class GroupMutation {
+  @Nullable private final DecryptedGroup       previousGroupState;
+  @Nullable private final DecryptedGroupChange groupChange;
+  @NonNull  private final DecryptedGroup       newGroupState;
+
+  public GroupMutation(@Nullable DecryptedGroup previousGroupState, @Nullable DecryptedGroupChange groupChange, @NonNull DecryptedGroup newGroupState) {
+    this.previousGroupState = previousGroupState;
+    this.groupChange        = groupChange;
+    this.newGroupState      = newGroupState;
+  }
+
+  public @Nullable DecryptedGroup getPreviousGroupState() {
+    return previousGroupState;
+  }
+
+  public @Nullable DecryptedGroupChange getGroupChange() {
+    return groupChange;
+  }
+
+  public @NonNull DecryptedGroup getNewGroupState() {
+    return newGroupState;
+  }
+}

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

@@ -49,12 +49,13 @@ public final class GroupProtoUtil {
   }
 
   public static DecryptedGroupV2Context createDecryptedGroupV2Context(@NonNull GroupMasterKey masterKey,
-                                                                      @NonNull DecryptedGroup decryptedGroup,
+                                                                      @NonNull GroupMutation groupMutation,
-                                                                      @Nullable DecryptedGroupChange plainGroupChange,
                                                                       @Nullable GroupChange signedServerChange)
   {
-    int revision = plainGroupChange != null ? plainGroupChange.getRevision() : decryptedGroup.getRevision();
+    DecryptedGroupChange                       plainGroupChange = groupMutation.getGroupChange();
-    SignalServiceProtos.GroupContextV2.Builder contextBuilder = SignalServiceProtos.GroupContextV2.newBuilder()
+    DecryptedGroup                             decryptedGroup   = groupMutation.getNewGroupState();
+    int                                        revision         = plainGroupChange != null ? plainGroupChange.getRevision() : decryptedGroup.getRevision();
+    SignalServiceProtos.GroupContextV2.Builder contextBuilder   = SignalServiceProtos.GroupContextV2.newBuilder()
                                                                                                   .setMasterKey(ByteString.copyFrom(masterKey.serialize()))
                                                                                                   .setRevision(revision);
 
@@ -66,6 +67,10 @@ public final class GroupProtoUtil {
                                                                      .setContext(contextBuilder.build())
                                                                      .setGroupState(decryptedGroup);
 
+    if (groupMutation.getPreviousGroupState() != null) {
+      builder.setPreviousGroupState(groupMutation.getPreviousGroupState());
+    }
+
     if (plainGroupChange != null) {
       builder.setChange(plainGroupChange);
     }

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

@@ -23,6 +23,7 @@ import org.thoughtcrime.securesms.database.RecipientDatabase;
 import org.thoughtcrime.securesms.database.model.databaseprotos.DecryptedGroupV2Context;
 import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
 import org.thoughtcrime.securesms.groups.GroupId;
+import org.thoughtcrime.securesms.groups.GroupMutation;
 import org.thoughtcrime.securesms.groups.GroupNotAMemberException;
 import org.thoughtcrime.securesms.groups.GroupProtoUtil;
 import org.thoughtcrime.securesms.groups.GroupsV2Authorization;
@@ -226,9 +227,9 @@ public final class GroupsV2StateProcessor {
       determineProfileSharing(inputGroupState, newLocalState);
       if (localState != null && localState.getRevision() == GroupsV2StateProcessor.RESTORE_PLACEHOLDER_REVISION) {
         Log.i(TAG, "Inserting single update message for restore placeholder");
-        insertUpdateMessages(timestamp, Collections.singleton(new LocalGroupLogEntry(newLocalState, null)));
+        insertUpdateMessages(timestamp, null, Collections.singleton(new LocalGroupLogEntry(newLocalState, null)));
       } else {
-        insertUpdateMessages(timestamp, advanceGroupStateResult.getProcessedLogEntries());
+        insertUpdateMessages(timestamp, localState, advanceGroupStateResult.getProcessedLogEntries());
       }
       persistLearnedProfileKeys(inputGroupState);
 
@@ -260,7 +261,7 @@ public final class GroupsV2StateProcessor {
                                                                       .addDeleteMembers(UuidUtil.toByteString(selfUuid))
                                                                       .build();
 
-      DecryptedGroupV2Context    decryptedGroupV2Context = GroupProtoUtil.createDecryptedGroupV2Context(masterKey, simulatedGroupState, simulatedGroupChange, null);
+      DecryptedGroupV2Context    decryptedGroupV2Context = GroupProtoUtil.createDecryptedGroupV2Context(masterKey, new GroupMutation(decryptedGroup, simulatedGroupChange, simulatedGroupState), null);
       OutgoingGroupUpdateMessage leaveMessage            = new OutgoingGroupUpdateMessage(groupRecipient,
                                                                                           decryptedGroupV2Context,
                                                                                           null,
@@ -362,13 +363,17 @@ public final class GroupsV2StateProcessor {
       }
     }
 
-    private void insertUpdateMessages(long timestamp, Collection<LocalGroupLogEntry> processedLogEntries) {
+    private void insertUpdateMessages(long timestamp,
+                                      @Nullable DecryptedGroup previousGroupState,
+                                      Collection<LocalGroupLogEntry> processedLogEntries)
+    {
       for (LocalGroupLogEntry entry : processedLogEntries) {
         if (entry.getChange() != null && DecryptedGroupUtil.changeIsEmptyExceptForProfileKeyChanges(entry.getChange()) && !DecryptedGroupUtil.changeIsEmpty(entry.getChange())) {
           Log.d(TAG, "Skipping profile key changes only update message");
         } else {
-          storeMessage(GroupProtoUtil.createDecryptedGroupV2Context(masterKey, entry.getGroup(), entry.getChange(), null), timestamp);
+          storeMessage(GroupProtoUtil.createDecryptedGroupV2Context(masterKey, new GroupMutation(previousGroupState, entry.getChange(), entry.getGroup()), null), timestamp);
         }
+        previousGroupState = entry.getGroup();
       }
     }
 

app/src/main/proto/Database.proto

@@ -28,9 +28,10 @@ import "SignalService.proto";
 import "DecryptedGroups.proto";
 
 message DecryptedGroupV2Context {
-    signalservice.GroupContextV2 context    = 1;
+    signalservice.GroupContextV2 context            = 1;
-    DecryptedGroupChange         change     = 2;
+    DecryptedGroupChange         change             = 2;
-    DecryptedGroup               groupState = 3;
+    DecryptedGroup               groupState         = 3;
+    DecryptedGroup               previousGroupState = 4;
 }
 
 message TemporalAuthCredentialResponse {

app/src/main/res/values/strings.xml

@@ -1013,6 +1013,12 @@
     <string name="MessageRecord_the_group_link_has_been_turned_on_with_admin_approval_off">The group link has been turned on with admin approval off.</string>
     <string name="MessageRecord_the_group_link_has_been_turned_on_with_admin_approval_on">The group link has been turned on with admin approval on.</string>
     <string name="MessageRecord_the_group_link_has_been_turned_off">The group link has been turned off.</string>
+    <string name="MessageRecord_you_turned_off_admin_approval_for_the_group_link">You turned off admin approval for the group link.</string>
+    <string name="MessageRecord_s_turned_off_admin_approval_for_the_group_link">%1$s turned off admin approval for the group link.</string>
+    <string name="MessageRecord_the_admin_approval_for_the_group_link_has_been_turned_off">The admin approval for the group link has been turned off.</string>
+    <string name="MessageRecord_you_turned_on_admin_approval_for_the_group_link">You turned on admin approval for the group link.</string>
+    <string name="MessageRecord_s_turned_on_admin_approval_for_the_group_link">%1$s turned on admin approval for the group link.</string>
+    <string name="MessageRecord_the_admin_approval_for_the_group_link_has_been_turned_on">The admin approval for the group link has been turned on.</string>
 
     <!-- GV2 group link reset -->
     <string name="MessageRecord_you_reset_the_group_link">You reset the group link.</string>

app/src/test/java/org/thoughtcrime/securesms/database/model/GroupsV2UpdateMessageProducerTest.java

@@ -3,6 +3,7 @@ package org.thoughtcrime.securesms.database.model;
 import android.app.Application;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
 import androidx.test.core.app.ApplicationProvider;
 
 import com.annimon.stream.Stream;
@@ -35,6 +36,7 @@ import static java.util.Collections.emptyList;
 import static java.util.Collections.singletonList;
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
@@ -921,6 +923,56 @@ public final class GroupsV2UpdateMessageProducerTest {
     assertThat(describeChange(change), is(singletonList("The group link has been turned off.")));
   }
 
+  // Group link with known previous group state
+
+  @Test
+  public void group_link_access_from_unknown_to_administrator() {
+    assertEquals("You turned on the group link with admin approval on.", describeGroupLinkChange(you, AccessControl.AccessRequired.UNKNOWN, AccessControl.AccessRequired.ADMINISTRATOR));
+    assertEquals("Alice turned on the group link with admin approval on.", describeGroupLinkChange(alice, AccessControl.AccessRequired.UNKNOWN, AccessControl.AccessRequired.ADMINISTRATOR));
+    assertEquals("The group link has been turned on with admin approval on.", describeGroupLinkChange(null, AccessControl.AccessRequired.UNKNOWN, AccessControl.AccessRequired.ADMINISTRATOR));
+  }
+
+  @Test
+  public void group_link_access_from_administrator_to_unsatisfiable() {
+    assertEquals("You turned off the group link.", describeGroupLinkChange(you, AccessControl.AccessRequired.ADMINISTRATOR, AccessControl.AccessRequired.UNSATISFIABLE));
+    assertEquals("Bob turned off the group link.", describeGroupLinkChange(bob, AccessControl.AccessRequired.ADMINISTRATOR, AccessControl.AccessRequired.UNSATISFIABLE));
+    assertEquals("The group link has been turned off.", describeGroupLinkChange(null, AccessControl.AccessRequired.ADMINISTRATOR, AccessControl.AccessRequired.UNSATISFIABLE));
+  }
+
+  @Test
+  public void group_link_access_from_unsatisfiable_to_administrator() {
+    assertEquals("You turned on the group link with admin approval on.", describeGroupLinkChange(you, AccessControl.AccessRequired.UNSATISFIABLE, AccessControl.AccessRequired.ADMINISTRATOR));
+    assertEquals("Alice turned on the group link with admin approval on.", describeGroupLinkChange(alice, AccessControl.AccessRequired.UNSATISFIABLE, AccessControl.AccessRequired.ADMINISTRATOR));
+    assertEquals("The group link has been turned on with admin approval on.", describeGroupLinkChange(null, AccessControl.AccessRequired.UNSATISFIABLE, AccessControl.AccessRequired.ADMINISTRATOR));
+  }
+
+  @Test
+  public void group_link_access_from_administrator_to_any() {
+    assertEquals("You turned off admin approval for the group link.", describeGroupLinkChange(you, AccessControl.AccessRequired.ADMINISTRATOR, AccessControl.AccessRequired.ANY));
+    assertEquals("Bob turned off admin approval for the group link.", describeGroupLinkChange(bob, AccessControl.AccessRequired.ADMINISTRATOR, AccessControl.AccessRequired.ANY));
+    assertEquals("The admin approval for the group link has been turned off.", describeGroupLinkChange(null, AccessControl.AccessRequired.ADMINISTRATOR, AccessControl.AccessRequired.ANY));
+  }
+
+  @Test
+  public void group_link_access_from_any_to_administrator() {
+    assertEquals("You turned on admin approval for the group link.", describeGroupLinkChange(you, AccessControl.AccessRequired.ANY, AccessControl.AccessRequired.ADMINISTRATOR));
+    assertEquals("Bob turned on admin approval for the group link.", describeGroupLinkChange(bob, AccessControl.AccessRequired.ANY, AccessControl.AccessRequired.ADMINISTRATOR));
+    assertEquals("The admin approval for the group link has been turned on.", describeGroupLinkChange(null, AccessControl.AccessRequired.ANY, AccessControl.AccessRequired.ADMINISTRATOR));
+  }
+
+  private String describeGroupLinkChange(@Nullable UUID editor, @NonNull AccessControl.AccessRequired fromAccess, AccessControl.AccessRequired toAccess){
+    DecryptedGroup       previousGroupState = DecryptedGroup.newBuilder()
+                                                            .setAccessControl(AccessControl.newBuilder()
+                                                                                           .setAddFromInviteLink(fromAccess))
+                                                            .build();
+    DecryptedGroupChange change             = (editor != null ? changeBy(editor) : changeByUnknown()).inviteLinkAccess(toAccess)
+                                                                                                     .build();
+
+    List<String> strings = describeChange(previousGroupState, change);
+    assertEquals(1, strings.size());
+    return strings.get(0);
+  }
+
   // Group link reset
 
   @Test
@@ -1271,8 +1323,14 @@ public final class GroupsV2UpdateMessageProducerTest {
   } 
   
   private @NonNull List<String> describeChange(@NonNull DecryptedGroupChange change) {
+    return describeChange(null, change);
+  }
+
+  private @NonNull List<String> describeChange(@Nullable DecryptedGroup previousGroupState,
+                                               @NonNull DecryptedGroupChange change)
+  {
     MainThreadUtil.setMainThread(false);
-    return Stream.of(producer.describeChanges(change))
+    return Stream.of(producer.describeChanges(previousGroupState, change))
                  .map(UpdateDescription::getString)
                  .toList();
   }
@@ -1291,7 +1349,7 @@ public final class GroupsV2UpdateMessageProducerTest {
   }
 
   private void assertSingleChangeMentioning(DecryptedGroupChange change, List<UUID> expectedMentions) {
-    List<UpdateDescription> changes = producer.describeChanges(change);
+    List<UpdateDescription> changes = producer.describeChanges(null, change);
 
     assertThat(changes.size(), is(1));