From f3680ad80cdc1b54294cf7c44677f48087485b67 Mon Sep 17 00:00:00 2001 From: Jelle Zijlstra Date: Mon, 19 Oct 2026 12:34:30 -0700 Subject: [PATCH] gh-159739: Preserve the syntax error if metadata allocation fails Restore the original exception when optional syntax-error metadata cannot be allocated. Backport to 3.15 and 3.14. On 3.14, also remove the erroneous Py_DECREF(the_source): the N format unit already consumed that reference. --- .../2026-10-19-19-33-35.gh-issue-159739.1fc3af.rst | 2 ++ Parser/pegen.c | 1 + 2 files changed, 3 insertions(+) create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.1fc3af.rst diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.1fc3af.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.1fc3af.rst new file mode 100644 index 000000000000000..a02631f2da2f9b2 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-10-19-19-33-35.gh-issue-159739.1fc3af.rst @@ -0,0 +1,2 @@ +Preserve the original :exc:`SyntaxError` if allocating optional error metadata +fails. diff --git a/Parser/pegen.c b/Parser/pegen.c index bb14a1e78c5ad35..9643426fa74c885 100644 --- a/Parser/pegen.c +++ b/Parser/pegen.c @@ -1083,6 +1083,7 @@ _PyPegen_set_syntax_error_metadata(Parser *p) { ); if (!metadata) { PyErr_Clear(); + PyErr_SetRaisedException(exc); return; } PySyntaxErrorObject *syntax_error = (PySyntaxErrorObject *)exc;