Attempt to fix date headers overlaping scheduled messages.

app/src/main/java/org/thoughtcrime/securesms/conversation/ScheduledMessagesBottomSheet.kt

@@ -100,6 +100,8 @@ class ScheduledMessagesBottomSheet : FixedRoundedCornerBottomSheetDialogFragment
       setCondensedMode(ConversationItemDisplayMode.Condensed(ConversationItemDisplayMode.MessageMode.SCHEDULED))
     }
 
+    val stickyHeaders = StickyHeaderDecoration(messageAdapter, false, false, ConversationAdapter.HEADER_TYPE_INLINE_DATE)
+
     val list: RecyclerView = view.findViewById<RecyclerView>(R.id.scheduled_list).apply {
       layoutManager = SmoothScrollingLinearLayoutManager(requireContext(), true)
       adapter = messageAdapter
@@ -107,7 +109,7 @@ class ScheduledMessagesBottomSheet : FixedRoundedCornerBottomSheetDialogFragment
 
       doOnNextLayout {
         // Adding this without waiting for a layout pass would result in an indeterminate amount of padding added to the top of the view
-        addItemDecoration(StickyHeaderDecoration(messageAdapter, false, false, ConversationAdapter.HEADER_TYPE_INLINE_DATE))
+        addItemDecoration(stickyHeaders)
       }
     }
 
@@ -127,6 +129,9 @@ class ScheduledMessagesBottomSheet : FixedRoundedCornerBottomSheetDialogFragment
         } else if (!list.canScrollVertically(1)) {
           list.layoutManager?.scrollToPosition(0)
         }
+
+        stickyHeaders.invalidateCache()
+        list.invalidateItemDecorations()
       }
       recyclerViewColorizer.setChatColors(conversationRecipient.chatColors)
     }

app/src/main/java/org/thoughtcrime/securesms/util/StickyHeaderDecoration.java

@@ -200,6 +200,10 @@ public class StickyHeaderDecoration extends RecyclerView.ItemDecoration {
         ((LinearLayoutManager)parent.getLayoutManager()).getReverseLayout();
   }
 
+  public void invalidateCache() {
+    headerCache.clear();
+  }
+
   /**
    * The adapter to assist the {@link StickyHeaderDecoration} in creating and binding the header views.
    */