message: Correctly use GetSegmentOffset in validity segment fetch
diff: @@ -372,7 +372,8 @@ void ValidityFetchRow(ColumnSegment &segment, ColumnFetchState &state, row_t row
  D_ASSERT(row_id >= 0 && row_id < row_t(segment.count));
  auto &buffer_manager = BufferManager::GetBufferManager(segment.db);
  auto handle = buffer_manager.Pin(segment.block);
  - ValidityMask mask((validity_t *)handle->node->buffer);
  + auto dataptr = handle->node->buffer + segment.GetBlockOffset();
  + ValidityMask mask((validity_t *)dataptr);
  auto &result_mask = FlatVector::Validity(result);
  if (!mask.RowIsValidUnsafe(row_id)) {
  result_mask.SetInvalid(result_idx);
  