BlockList vs. "zero length" group names

Signal/src/ViewControllers/AppSettings/BlockListViewController.m

@@ -118,7 +118,8 @@ NS_ASSUME_NONNULL_BEGIN
 
         for (TSGroupModel *blockedGroup in blockedGroups) {
             UIImage *image = blockedGroup.groupImage ?: OWSGroupAvatarBuilder.defaultGroupImage;
-            NSString *groupName = blockedGroup.groupName ?: TSGroupThread.defaultGroupName;
+            NSString *groupName
+                = blockedGroup.groupName.length > 0 ? blockedGroup.groupName : TSGroupThread.defaultGroupName;
 
             [blockedGroupsSection addItem:[OWSTableItem
                                               itemWithCustomCellBlock:^{

Signal/translations/en.lproj/Localizable.strings

@@ -248,8 +248,8 @@
 /* Action sheet body when confirming you want to unblock a group */
 "BLOCK_LIST_UNBLOCK_GROUP_BODY" = "Existing members will be able to add you to the group again.";
 
-/* Action sheet title when confirming you want to unblock a group. Embeds the {{conversation title}}. */
-"BLOCK_LIST_UNBLOCK_GROUP_TITLE_FORMAT" = "Unblock This Group?";
+/* Action sheet title when confirming you want to unblock a group. */
+"BLOCK_LIST_UNBLOCK_GROUP_TITLE" = "Unblock This Group?";
 
 /* A format for the 'unblock conversation' action sheet title. Embeds the {{conversation title}}. */
 "BLOCK_LIST_UNBLOCK_TITLE_FORMAT" = "Unblock %@?";

SignalMessaging/utils/BlockListUIUtils.m

@@ -154,10 +154,11 @@ typedef void (^BlockAlertCompletionBlock)(UIAlertAction *action);
     OWSAssert(fromViewController);
     OWSAssert(blockingManager);
 
+    NSString *groupName = groupThread.name.length > 0 ? groupThread.name : TSGroupThread.defaultGroupName;
     NSString *title = [NSString
         stringWithFormat:NSLocalizedString(@"BLOCK_LIST_BLOCK_GROUP_TITLE_FORMAT",
                              @"A format for the 'block group' action sheet title. Embeds the {{group name}}."),
-        [self formatDisplayNameForAlertTitle:groupThread.name]];
+        [self formatDisplayNameForAlertTitle:groupName]];
 
     UIAlertController *actionSheetController =
         [UIAlertController alertControllerWithTitle:title
@@ -246,6 +247,9 @@ typedef void (^BlockAlertCompletionBlock)(UIAlertAction *action);
                                    DDLogError(@"Failed to leave blocked group with error: %@", error);
                                }
 
+                               NSString *groupName
+                                   = groupThread.name.length > 0 ? groupThread.name : TSGroupThread.defaultGroupName;
+
                                [self
                                    showOkAlertWithTitle:NSLocalizedString(@"BLOCK_LIST_VIEW_BLOCKED_GROUP_ALERT_TITLE",
                                                             @"The title of the 'group blocked' alert.")
@@ -256,7 +260,7 @@ typedef void (^BlockAlertCompletionBlock)(UIAlertAction *action);
                                                                     @"The message format of the 'conversation blocked' "
                                                                     @"alert. "
                                                                     @"Embeds the {{conversation title}}."),
-                                                            [self formatDisplayNameForAlertMessage:groupThread.name]]
+                                                            [self formatDisplayNameForAlertMessage:groupName]]
                                      fromViewController:fromViewController
                                         completionBlock:completionBlock];
                            }];
@@ -279,8 +283,9 @@ typedef void (^BlockAlertCompletionBlock)(UIAlertAction *action);
                                 completionBlock:completionBlock];
     } else if ([thread isKindOfClass:[TSGroupThread class]]) {
         TSGroupThread *groupThread = (TSGroupThread *)thread;
+        NSString *groupName = groupThread.name.length > 0 ? groupThread.name : TSGroupThread.defaultGroupName;
         [self showUnblockGroupActionSheet:groupThread.groupModel
-                              displayName:groupThread.name
+                              displayName:groupName
                        fromViewController:fromViewController
                           blockingManager:blockingManager
                           completionBlock:completionBlock];
@@ -398,11 +403,9 @@ typedef void (^BlockAlertCompletionBlock)(UIAlertAction *action);
     OWSAssert(fromViewController);
     OWSAssert(blockingManager);
 
-    NSString *title = [NSString
-        stringWithFormat:
-            NSLocalizedString(@"BLOCK_LIST_UNBLOCK_GROUP_TITLE_FORMAT",
-                @"Action sheet title when confirming you want to unblock a group. Embeds the {{conversation title}}."),
-        [self formatDisplayNameForAlertTitle:displayName]];
+    NSString *title =
+        [NSString stringWithFormat:NSLocalizedString(@"BLOCK_LIST_UNBLOCK_GROUP_TITLE",
+                                       @"Action sheet title when confirming you want to unblock a group.")];
 
     NSString *message = NSLocalizedString(
         @"BLOCK_LIST_UNBLOCK_GROUP_BODY", @"Action sheet body when confirming you want to unblock a group");

SignalMessaging/utils/ThreadUtil.m

@@ -221,8 +221,9 @@ NS_ASSUME_NONNULL_BEGIN
     OWSAssert(presentingViewController);
     OWSAssert(messageSender);
 
+    NSString *groupName = thread.name.length > 0 ? thread.name : TSGroupThread.defaultGroupName;
     NSString *title = [NSString
-        stringWithFormat:NSLocalizedString(@"GROUP_REMOVING", @"Modal text when removing a group"), thread.name];
+        stringWithFormat:NSLocalizedString(@"GROUP_REMOVING", @"Modal text when removing a group"), groupName];
     UIAlertController *removingFromGroup =
         [UIAlertController alertControllerWithTitle:title message:nil preferredStyle:UIAlertControllerStyleAlert];
     [presentingViewController presentViewController:removingFromGroup animated:YES completion:nil];

SignalServiceKit/src/Contacts/Threads/TSGroupThread.m

@@ -175,6 +175,10 @@ NSString *const TSGroupThread_NotificationKey_UniqueId = @"TSGroupThread_Notific
 
 - (NSString *)name
 {
+    // TODO sometimes groupName is set to the empty string. I'm hesitent to change
+    // the semantics here until we have time to thouroughly test the fallout.
+    // Instead, see the `groupNameOrDefault` which is appropriate for use when displaying
+    // text corresponding to a group.
     return self.groupModel.groupName ?: self.class.defaultGroupName;
 }