From 972ab0327675e695373fc6272d5ac24e187579ad Mon Sep 17 00:00:00 2001 From: Pablo Galindo Date: Mon, 8 Jun 2020 01:47:37 +0100 Subject: bpo-40904: Fix segfault in the new parser with f-string containing yield statements with no value (GH-20701) --- Lib/test/test_fstring.py | 2 ++ .../next/Core and Builtins/2020-06-08-01-08-57.bpo-40904.76qQzo.rst | 2 ++ Parser/pegen/parse_string.c | 3 +++ 3 files changed, 7 insertions(+) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2020-06-08-01-08-57.bpo-40904.76qQzo.rst diff --git a/Lib/test/test_fstring.py b/Lib/test/test_fstring.py index ea4e589..9048e89 100644 --- a/Lib/test/test_fstring.py +++ b/Lib/test/test_fstring.py @@ -725,9 +725,11 @@ non-important content # a function into a generator def fn(y): f'y:{yield y*2}' + f'{yield}' g = fn(4) self.assertEqual(next(g), 8) + self.assertEqual(next(g), None) def test_yield_send(self): def fn(x): diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-06-08-01-08-57.bpo-40904.76qQzo.rst b/Misc/NEWS.d/next/Core and Builtins/2020-06-08-01-08-57.bpo-40904.76qQzo.rst new file mode 100644 index 0000000..09009b1 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2020-06-08-01-08-57.bpo-40904.76qQzo.rst @@ -0,0 +1,2 @@ +Fix possible segfault in the new PEG parser when parsing f-string containing +yield statements with no value (:code:`f"{yield}"`). Patch by Pablo Galindo diff --git a/Parser/pegen/parse_string.c b/Parser/pegen/parse_string.c index efe82df..94241e1 100644 --- a/Parser/pegen/parse_string.c +++ b/Parser/pegen/parse_string.c @@ -278,6 +278,9 @@ static void fstring_shift_argument(expr_ty parent, arg_ty args, int lineno, int static inline void shift_expr(expr_ty parent, expr_ty n, int line, int col) { + if (n == NULL) { + return; + } if (parent->lineno < n->lineno) { col = 0; } -- cgit v0.12