Table: Consider sparsity flags when domain match

Author: nikicc

Orange/data/table.py

@@ -398,6 +398,12 @@ def get_columns(row_indices, src_cols, n_rows, dtype=np.float64, is_sparse=False
                     table = cls.from_table_rows(source, row_indices)
                     # assure resulting domain is the instance passed on input
                     table.domain = domain
+                    # Since sparse flags are not considered when checking for domain equality,
+                    # we need to assure correct density manually through domain conversion suggestions.
+                    conversion = domain.get_conversion(source.domain)
+                    table.X = array_transform(table.X, conversion.sparse_X)
+                    table.Y = array_transform(table.Y, conversion.sparse_Y)
+                    table.metas = array_transform(table.metas, conversion.sparse_metas)
                     return table
 
                 if isinstance(row_indices, slice):