Fix optional patterns without default values: Newpattern only if not …

…set.
Mathics3 · Nov 19, 2024 · e1dee54 · e1dee54
1 parent c1999ce
commit e1dee54
Showing 1 changed file with 4 additions and 3 deletions.
diff --git a/mathics/core/pattern.py b/mathics/core/pattern.py
@@ -724,9 +724,10 @@ def match_expression_with_one_identity(
                 result = defaultvalue_expr.evaluate(evaluation)
                 assert result is not None
                 if result.sameQ(defaultvalue_expr):
-                    # The optional pattern has no default value
-                    # for the given position
-                    new_pattern = pat_elem
+                    if new_pattern is None:
+                        # The optional pattern has no default value
+                        # for the given position
+                        new_pattern = pat_elem
                 else:
                     optionals[key] = result
             else: