From d64d78be20ced6ac9de58e91e69eaba184e36e9b Mon Sep 17 00:00:00 2001 From: "Miss Islington (bot)" <31488909+miss-islington@users.noreply.github.com> Date: Fri, 4 Sep 2020 16:38:50 -0700 Subject: bpo-41531: Fix compilation of dict literals with more than 0xFFFF elements (GH-21850) (GH-22107) (cherry picked from commit c51db0ea40ddabaf5f771ea633b37fcf4c90a495) Co-authored-by: Pablo Galindo --- Lib/test/test_compile.py | 10 ++++++++++ .../Core and Builtins/2020-08-12-19-32-15.bpo-41531.WgPzjT.rst | 2 ++ Python/compile.c | 2 +- 3 files changed, 13 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Core and Builtins/2020-08-12-19-32-15.bpo-41531.WgPzjT.rst diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py index 566ca27..55716fd 100644 --- a/Lib/test/test_compile.py +++ b/Lib/test/test_compile.py @@ -750,6 +750,16 @@ if 1: self.assertEqual(None, opcodes[0].argval) self.assertEqual('RETURN_VALUE', opcodes[1].opname) + def test_big_dict_literal(self): + # The compiler has a flushing point in "compiler_dict" that calls compiles + # a portion of the dictionary literal when the loop that iterates over the items + # reaches 0xFFFF elements but the code was not including the boundary element, + # dropping the key at position 0xFFFF. See bpo-41531 for more information + + dict_size = 0xFFFF + 1 + the_dict = "{" + ",".join(f"{x}:{x}" for x in range(dict_size)) + "}" + self.assertEqual(len(eval(the_dict)), dict_size) + class TestExpressionStackSize(unittest.TestCase): # These tests check that the computed stack size for a code object # stays within reasonable bounds (see issue #21523 for an example diff --git a/Misc/NEWS.d/next/Core and Builtins/2020-08-12-19-32-15.bpo-41531.WgPzjT.rst b/Misc/NEWS.d/next/Core and Builtins/2020-08-12-19-32-15.bpo-41531.WgPzjT.rst new file mode 100644 index 0000000..8544664 --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2020-08-12-19-32-15.bpo-41531.WgPzjT.rst @@ -0,0 +1,2 @@ +Fix a bug that was dropping keys when compiling dict literals with more than +0xFFFF elements. Patch by Pablo Galindo. diff --git a/Python/compile.c b/Python/compile.c index 7ec92e0..51af28b 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -3890,7 +3890,7 @@ compiler_dict(struct compiler *c, expr_ty e) } else { if (elements == 0xFFFF) { - if (!compiler_subdict(c, e, i - elements, i)) { + if (!compiler_subdict(c, e, i - elements, i + 1)) { return 0; } if (have_dict) { -- cgit v0.12