https://github.com/python/cpython/commit/255e79fa955ac5ffef9eb27087e8b1373e98e3bd commit: 255e79fa955ac5ffef9eb27087e8b1373e98e3bd branch: main author: Stan Ulbrych <[email protected]> committer: JelleZijlstra <[email protected]> date: 2026-03-09T10:37:23-07:00 summary:
gh-143055: Fix crash in AST unparser when unparsing dict comprehension unpacking (#145556) files: A Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-16-16-17.gh-issue-143055.qDUFlY.rst M Doc/conf.py M Lib/_ast_unparse.py M Lib/test/test_future_stmt/test_future.py M Lib/test/test_unparse.py M Python/ast_unparse.c diff --git a/Doc/conf.py b/Doc/conf.py index 26497083d28e47..6f66ed68c52e83 100644 --- a/Doc/conf.py +++ b/Doc/conf.py @@ -557,6 +557,7 @@ # mapping unique short aliases to a base URL and a prefix. # https://www.sphinx-doc.org/en/master/usage/extensions/extlinks.html extlinks = { + "oss-fuzz": ("https://issues.oss-fuzz.com/issues/%s";, "#%s"), "pypi": ("https://pypi.org/project/%s/";, "%s"), "source": (SOURCE_URI, "%s"), } diff --git a/Lib/_ast_unparse.py b/Lib/_ast_unparse.py index 0c3b1d3a9108a3..916bb25d74dee9 100644 --- a/Lib/_ast_unparse.py +++ b/Lib/_ast_unparse.py @@ -738,9 +738,13 @@ def visit_SetComp(self, node): def visit_DictComp(self, node): with self.delimit("{", "}"): - self.traverse(node.key) - self.write(": ") - self.traverse(node.value) + if node.value: + self.traverse(node.key) + self.write(": ") + self.traverse(node.value) + else: + self.write("**") + self.traverse(node.key) for gen in node.generators: self.traverse(gen) diff --git a/Lib/test/test_future_stmt/test_future.py b/Lib/test/test_future_stmt/test_future.py index 71f1e616116d81..faa3a2bfe121dc 100644 --- a/Lib/test/test_future_stmt/test_future.py +++ b/Lib/test/test_future_stmt/test_future.py @@ -349,6 +349,8 @@ def test_annotations(self): eq("(i ** 2 + j for i in (1, 2, 3) for j in (1, 2, 3))") eq("{i: 0 for i in (1, 2, 3)}") eq("{i: j for i, j in ((1, 'a'), (2, 'b'), (3, 'c'))}") + eq("{**x for x in ()}") + eq("[*x for x in ()]") eq("[(x, y) for x, y in (a, b)]") eq("[(x,) for x, in (a,)]") eq("Python3 > Python2 > COBOL") diff --git a/Lib/test/test_unparse.py b/Lib/test/test_unparse.py index 35e4652a87b423..dcaad49ffab5d2 100644 --- a/Lib/test/test_unparse.py +++ b/Lib/test/test_unparse.py @@ -403,6 +403,11 @@ def test_set_comprehension(self): def test_dict_comprehension(self): self.check_ast_roundtrip("{x: x*x for x in range(10)}") + def test_dict_comprehension_unpacking(self): + self.check_ast_roundtrip("{**x for x in ()}") + self.check_ast_roundtrip("{**x for x in range(10)}") + self.check_ast_roundtrip("[*x for x in ()]") + def test_class_decorators(self): self.check_ast_roundtrip(class_decorator) diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-16-16-17.gh-issue-143055.qDUFlY.rst b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-16-16-17.gh-issue-143055.qDUFlY.rst new file mode 100644 index 00000000000000..9b55459bffdea8 --- /dev/null +++ b/Misc/NEWS.d/next/Core_and_Builtins/2026-03-05-16-16-17.gh-issue-143055.qDUFlY.rst @@ -0,0 +1,2 @@ +Fix crash in AST unparser when unparsing dict comprehension unpacking. +Found by OSS Fuzz in :oss-fuzz:`489790200`. diff --git a/Python/ast_unparse.c b/Python/ast_unparse.c index c25699978cf651..6050c351cff68f 100644 --- a/Python/ast_unparse.c +++ b/Python/ast_unparse.c @@ -464,9 +464,15 @@ static int append_ast_dictcomp(PyUnicodeWriter *writer, expr_ty e) { APPEND_CHAR('{'); - APPEND_EXPR(e->v.DictComp.key, PR_TEST); - APPEND_STR(": "); - APPEND_EXPR(e->v.DictComp.value, PR_TEST); + if (e->v.DictComp.value) { + APPEND_EXPR(e->v.DictComp.key, PR_TEST); + APPEND_STR(": "); + APPEND_EXPR(e->v.DictComp.value, PR_TEST); + } + else { + APPEND_STR("**"); + APPEND_EXPR(e->v.DictComp.key, PR_TEST); + } APPEND(comprehensions, e->v.DictComp.generators); APPEND_CHAR_FINISH('}'); } _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
