Brent Westbrook 835e31b3ff Fix syntax error false positive on alternative match patterns (#21362) ...

Summary
--

Fixes #21360 by using the union of names instead of overwriting them, as
Micha suggested originally on #21104.

This avoids overwriting the `n` name in the `Subscript` by the empty set
of names visited in the nested OR pattern before visiting the other arm
of the outer OR pattern.

Test Plan
--

A new inline test case taken from the issue

2025-11-10 10:51:51 -05:00

..

all_async_comprehension_py310.py

[syntax-errors] Async comprehension in sync comprehension (#17177)

2025-04-08 12:50:52 -04:00

ambiguous_lpar_with_items_binary_expr.py

Consider binary expr for parenthesized with items parsing (#11012)

2024-04-18 21:39:30 +05:30

ambiguous_lpar_with_items_if_expr.py

Consider if expression for parenthesized with items parsing (#11010)

2024-04-18 14:30:15 +00:00

ann_assign_stmt_simple_target.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

args_unparenthesized_generator.py

[parser] Flag single unparenthesized generator expr with trailing comma in arguments. (#17893)

2025-05-07 14:11:35 -04:00

assign_stmt_starred_expr_value.py

[syntax-errors] Detect single starred expression assignment x = *y (#17624)

2025-04-30 15:04:00 -04:00

assign_targets_terminator.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

async_for_statement.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

async_function_definition.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

async_with_statement.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

class_def_arguments.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

class_keyword_in_case_pattern.py

[syntax-errors] Fix multiple assignment for class keyword argument (#17184)

2025-04-03 17:32:39 -04:00

class_type_params_py312.py

[syntax-errors] Type parameter lists before Python 3.12 (#16479)

2025-03-05 13:19:09 +00:00

comma_separated_regular_list_terminator.py

Implement re-lexing logic for better error recovery (#11845)

2024-06-17 06:47:00 +00:00

debug_rename_import.py

[syntax-errors] Store to or delete __debug__ (#16984)

2025-03-29 12:07:20 -04:00

decorator_async_function.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

decorator_await_expression_py39.py

[syntax-errors] Improve error message and range for pre-PEP-614 decorator syntax errors (#16581)

2025-03-17 11:17:27 +00:00

decorator_expression_dotted_ident_py38.py

[syntax-errors] Named expressions in decorators before Python 3.9 (#16386)

2025-03-05 17:08:18 +00:00

decorator_expression_eval_hack_py38.py

[syntax-errors] Named expressions in decorators before Python 3.9 (#16386)

2025-03-05 17:08:18 +00:00

decorator_expression_identity_hack_py38.py

[syntax-errors] Named expressions in decorators before Python 3.9 (#16386)

2025-03-05 17:08:18 +00:00

decorator_expression_py39.py

[syntax-errors] Named expressions in decorators before Python 3.9 (#16386)

2025-03-05 17:08:18 +00:00

del_debug_py38.py

[syntax-errors] Store to or delete __debug__ (#16984)

2025-03-29 12:07:20 -04:00

del_targets_terminator.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

different_match_pattern_bindings.py

[syntax-errors] Alternative match patterns bind different names (#20682)

2025-10-17 21:35:48 +00:00

dotted_name_normalized_spaces.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

duplicate_match_key_attr.py

[syntax-errors] Detect duplicate keys in match mapping patterns (#17129)

2025-04-03 10:22:37 -04:00

except_star_py311.py

[syntax-errors] except* before Python 3.11 (#16446)

2025-03-02 18:20:18 +00:00

except_stmt_as_name_soft_keyword.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

except_stmt_unparenthesized_tuple_no_as_py314.py

Make syntax error for unparenthesized except tuples version specific to before 3.14 (#17660)

2025-04-29 07:55:30 -05:00

for_in_target_valid_expr.py

Add ExpressionContext for expression parsing (#11055)

2024-04-23 04:19:05 +00:00

for_iter_unpack_py38.py

[syntax-errors] Tuple unpacking in for statement iterator clause before Python 3.9 (#16558)

2025-03-13 15:55:17 -04:00

for_iter_unpack_py39.py

[syntax-errors] Tuple unpacking in for statement iterator clause before Python 3.9 (#16558)

2025-03-13 15:55:17 -04:00

from_import_no_space.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

from_import_soft_keyword_module_name.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

from_import_stmt_terminator.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

fstring_format_spec_terminator.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

function_def_parameter_range.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

function_def_parenthesized_return_types.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

function_def_valid_return_expr.py

[syntax-errors] Invalid syntax in annotations (#17101)

2025-04-03 17:56:55 -04:00

function_type_params_py312.py

[syntax-errors] Type parameter lists before Python 3.12 (#16479)

2025-03-05 13:19:09 +00:00

global_stmt.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

import_as_name_soft_keyword.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

import_from_star.py

[syntax-errors]: import from * only allowed at module scope (F406) (#20166)

2025-09-16 15:53:28 -04:00

import_stmt_terminator.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

irrefutable_case_pattern_at_end.py

[syntax-errors] Irrefutable case pattern before final case (#16905)

2025-03-26 12:27:16 -04:00

iter_unpack_return_py37.py

[syntax-errors] Tuple unpacking in return and yield before Python 3.8 (#16485)

2025-03-06 11:57:20 -05:00

iter_unpack_return_py38.py

[syntax-errors] Tuple unpacking in return and yield before Python 3.8 (#16485)

2025-03-06 11:57:20 -05:00

iter_unpack_yield_py37.py

[syntax-errors] Tuple unpacking in return and yield before Python 3.8 (#16485)

2025-03-06 11:57:20 -05:00

iter_unpack_yield_py38.py

[syntax-errors] Tuple unpacking in return and yield before Python 3.8 (#16485)

2025-03-06 11:57:20 -05:00

lambda_with_no_parameters.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

lambda_with_valid_body.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

match_after_py310.py

Allow passing ParseOptions to inline tests (#16357)

2025-02-27 10:23:15 -05:00

match_as_pattern_soft_keyword.py

[syntax-errors] Irrefutable case pattern before final case (#16905)

2025-03-26 12:27:16 -04:00

match_as_pattern.py

[syntax-errors] Irrefutable case pattern before final case (#16905)

2025-03-26 12:27:16 -04:00

match_attr_pattern_soft_keyword.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

match_classify_as_identifier_1.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

match_classify_as_identifier_2.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

match_classify_as_keyword_1.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

match_classify_as_keyword_2.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

match_classify_as_keyword_or_identifier.py

Maintain synchronicity between the lexer and the parser (#11457)

2024-06-03 18:23:50 +05:30

match_sequence_pattern_parentheses_terminator.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

match_sequence_pattern_terminator.py

[syntax-errors] Irrefutable case pattern before final case (#16905)

2025-03-26 12:27:16 -04:00

match_stmt_subject_expr.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

match_stmt_valid_guard_expr.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

multiple_assignment_in_case_pattern.py

[syntax-errors] Multiple assignments in case pattern (#16957)

2025-03-26 13:02:42 -04:00

multiple_starred_assignment_target.py

[syntax-errors]: multiple-starred-expressions (F622) (#20243)

2025-09-24 19:32:55 +00:00

nested_alternative_patterns.py

Fix syntax error false positive on alternative match patterns (#21362)

2025-11-10 10:51:51 -05:00

nested_async_comprehension_py310.py

Refactor semantic syntax error scope handling (#17314)

2025-04-09 14:23:29 -04:00

nested_async_comprehension_py311.py

[syntax-errors] Async comprehension in sync comprehension (#17177)

2025-04-08 12:50:52 -04:00

non_duplicate_type_parameter_names.py

[syntax-errors] Duplicate type parameter names (#16858)

2025-03-21 15:06:22 -04:00

non_nested_quote_in_format_spec_py311.py

Fix syntax error false positives for escapes and quotes in f-strings (#20867)

2025-10-15 09:23:16 -04:00

non_rebound_comprehension_variable.py

[syntax-errors] Start detecting compile-time syntax errors (#16106)

2025-03-21 14:45:25 -04:00

nonlocal_declaration_at_module_level.py

[syntax-errors] nonlocal declaration at module level (#17559)

2025-04-24 16:11:46 -04:00

nonlocal_stmt.py

[syntax-errors] nonlocal declaration at module level (#17559)

2025-04-24 16:11:46 -04:00

param_with_annotation.py

Implement template strings (#17851)

2025-05-30 15:00:56 -05:00

param_with_default.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

param_with_star_annotation_py310.py

[syntax-errors] Fix star annotation before Python 3.11 (#16878)

2025-03-20 17:44:52 -04:00

param_with_star_annotation_py311.py

[syntax-errors] Star annotations before Python 3.11 (#16545)

2025-03-14 15:20:44 +00:00

param_with_star_annotation.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

params_non_default_after_star.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

params_seen_keyword_only_param_after_star.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

parenthesized_context_manager_py39.py

[syntax-errors] Parenthesized context managers before Python 3.9 (#16523)

2025-03-17 08:54:55 -04:00

parenthesized_kwarg_py37.py

[syntax-errors] Parenthesized keyword argument names after Python 3.8 (#16482)

2025-03-06 12:18:13 -05:00

parenthesized_named_expr_index_py38.py

[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)

2025-03-14 15:06:42 -04:00

parenthesized_named_expr_py38.py

[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)

2025-03-14 15:06:42 -04:00

parenthesized_star_index_py310.py

[syntax-errors] Fix false positive for parenthesized tuple index (#16948)

2025-03-24 10:34:38 -04:00

pep701_f_string_py311.py

Fix syntax error false positives for escapes and quotes in f-strings (#20867)

2025-10-15 09:23:16 -04:00

pep701_f_string_py312.py

[syntax-errors] PEP 701 f-strings before Python 3.12 (#16543)

2025-03-18 11:12:15 -04:00

pep750_t_string_py314.py

Implement template strings (#17851)

2025-05-30 15:00:56 -05:00

pos_only_py38.py

[syntax-errors] Positional-only parameters before Python 3.8 (#16481)

2025-03-05 13:46:43 +00:00

read_from_debug.py

[syntax-errors] Store to or delete __debug__ (#16984)

2025-03-29 12:07:20 -04:00

simple_stmts_in_block.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

simple_stmts_with_semicolons.py

Replace LALRPOP parser with hand-written parser (#10036)

2024-04-18 17:57:39 +05:30

single_parenthesized_item_context_manager_py38.py

Fix syntax error false positives on parenthesized context managers (#20846)

2025-10-13 14:13:27 -04:00

single_star_in_tuple.py

[syntax-errors] Starred expressions in return, yield, and for (#17134)

2025-04-02 08:38:25 -04:00

single_starred_assignment_target.py

[syntax-errors] Single starred assignment target (#17024)

2025-03-29 12:35:47 -04:00

star_index_py311.py

[syntax-errors] Star expression in index before Python 3.11 (#16544)

2025-03-14 14:51:34 +00:00

template_strings_py314.py

Disallow implicit concatenation of t-strings and other string types (#19485)

2025-07-27 12:41:03 +00:00

tuple_context_manager_py38.py

[syntax-errors] Parenthesized context managers before Python 3.9 (#16523)

2025-03-17 08:54:55 -04:00

type_param_default_py313.py

[syntax-errors] Type parameter defaults before Python 3.13 (#16447)

2025-03-04 16:53:38 +00:00

type_param_param_spec.py

Add support for PEP 696 syntax (#11120)

2024-04-26 09:47:29 +02:00

type_param_type_var_tuple.py

Add support for PEP 696 syntax (#11120)

2024-04-26 09:47:29 +02:00

type_param_type_var.py

Add support for PEP 696 syntax (#11120)

2024-04-26 09:47:29 +02:00

type_stmt_py312.py

[syntax-errors] type alias statements before Python 3.12 (#16478)

2025-03-04 17:20:10 +00:00

unparenthesized_named_expr_index_py39.py

[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)

2025-03-14 15:06:42 -04:00

unparenthesized_named_expr_py39.py

[syntax-errors] Unparenthesized assignment expressions in sets and indexes (#16404)

2025-03-14 15:06:42 -04:00

valid_annotation_class.py

[syntax-errors] Extend annotation checks to await (#17282)

2025-04-08 08:55:43 -04:00

valid_annotation_function_py313.py

[syntax-errors] Extend annotation checks to await (#17282)

2025-04-08 08:55:43 -04:00

valid_annotation_py313.py

[syntax-errors] Check annotations in annotated assignments (#17283)

2025-04-08 08:56:25 -04:00

valid_future_feature.py

[syntax-errors]: future-feature-not-defined (F407) (#20554)

2025-09-25 13:52:24 -04:00

walrus_py38.py

[syntax-errors] Assignment expressions before Python 3.8 (#16383)

2025-02-28 17:13:46 -05:00