Bug fixs.

lib/local_storage/sqflite_localpodcast.dart

@@ -318,9 +318,9 @@ class DBHelper {
     List<Map> list = await dbClient.rawQuery(
         "SELECT seconds FROM PlayHistory WHERE add_date > ? AND add_date < ?",
         [start, end]);
-    var sum = 0;
+    var sum = 0.0;
     if (list.isEmpty) {
-      sum = 0;
+      sum = 0.0;
     } else {
       for (var record in list) {
         sum += record['seconds'];

lib/util/custom_dropdown.dart

@@ -521,7 +521,7 @@ class _DropdownRoute<T> extends PopupRoute<_DropdownRouteResult<T>> {
     // it. This scroll offset is only accurate for fixed height menu items
     // (the default).
     final scrollOffset = preferredMenuHeight <= maxMenuHeight
-        ? 0
+        ? 0.0
         : math.max(0.0, selectedItemOffset - (buttonTop - menuTop));
 
     return _MenuLimits(menuTop, menuBottom, menuHeight, scrollOffset);