Issue #9011: Remove buggy and unnecessary ST->AST compilation code
dealing with unary minus applied to a constant. The removed code was
mutating the ST, causing a second compilation to fail. (The peephole
optimizer already takes care of optimizing this case, so there's no
lost optimization opportunity here.)
diff --git a/Lib/test/test_parser.py b/Lib/test/test_parser.py
index a36b544..071d362 100644
--- a/Lib/test/test_parser.py
+++ b/Lib/test/test_parser.py
@@ -484,8 +484,18 @@
st = parser.suite('a = "\\u1"')
self.assertRaises(SyntaxError, parser.compilest, st)
+ def test_issue_9011(self):
+ # Issue 9011: compilation of an unary minus expression changed
+ # the meaning of the ST, so that a second compilation produced
+ # incorrect results.
+ st = parser.expr('-3')
+ code1 = parser.compilest(st)
+ self.assertEqual(eval(code1), -3)
+ code2 = parser.compilest(st)
+ self.assertEqual(eval(code2), -3)
+
class ParserStackLimitTestCase(unittest.TestCase):
- """try to push the parser to/over it's limits.
+ """try to push the parser to/over its limits.
see http://bugs.python.org/issue1881 for a discussion
"""
def _nested_expression(self, level):