From 62bd97303eb6d1fb0109e4a57d38c2ba6b0be7ff Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Mon, 16 Aug 2021 11:34:23 -0700 Subject: Fix a SystemError in code.replace() (#27771) While the comment said 'We don't bother resizing localspluskinds', this would cause .replace() to crash when it happened. (Also types.CodeType(), but testing that is tedious, and this tests all code paths.) --- Lib/test/test_code.py | 9 +++++++++ Objects/codeobject.c | 8 +++++--- 2 files changed, 14 insertions(+), 3 deletions(-) diff --git a/Lib/test/test_code.py b/Lib/test/test_code.py index 2bdd7e7..9d6b465 100644 --- a/Lib/test/test_code.py +++ b/Lib/test/test_code.py @@ -320,6 +320,15 @@ class CodeTest(unittest.TestCase): with self.assertRaises(ValueError): co.replace(co_nlocals=co.co_nlocals + 1) + def test_shrinking_localsplus(self): + # Check that PyCode_NewWithPosOnlyArgs resizes both + # localsplusnames and localspluskinds, if an argument is a cell. + def func(arg): + return lambda: arg + code = func.__code__ + newcode = code.replace(co_name="func") # Should not raise SystemError + self.assertEqual(code, newcode) + def test_empty_linetable(self): def func(): pass diff --git a/Objects/codeobject.c b/Objects/codeobject.c index 3dc9fd7..ad8f13a 100644 --- a/Objects/codeobject.c +++ b/Objects/codeobject.c @@ -471,9 +471,11 @@ PyCode_NewWithPosOnlyArgs(int argcount, int posonlyargcount, int kwonlyargcount, localsplusnames, localspluskinds); } // If any cells were args then nlocalsplus will have shrunk. - // We don't bother resizing localspluskinds. - if (_PyTuple_Resize(&localsplusnames, nlocalsplus) < 0) { - goto error; + if (nlocalsplus != PyTuple_GET_SIZE(localsplusnames)) { + if (_PyTuple_Resize(&localsplusnames, nlocalsplus) < 0 + || _PyBytes_Resize(&localspluskinds, nlocalsplus) < 0) { + goto error; + } } struct _PyCodeConstructor con = { -- cgit v0.12