Issue #28727: Optimize pattern_richcompare() for a==a
A pattern is equal to itself.
diff --git a/Lib/test/test_re.py b/Lib/test/test_re.py
index 4fcd2d4..84131d2 100644
--- a/Lib/test/test_re.py
+++ b/Lib/test/test_re.py
@@ -1781,6 +1781,10 @@
def test_pattern_compare(self):
pattern1 = re.compile('abc', re.IGNORECASE)
+ # equal to itself
+ self.assertEqual(pattern1, pattern1)
+ self.assertFalse(pattern1 != pattern1)
+
# equal
re.purge()
pattern2 = re.compile('abc', re.IGNORECASE)
diff --git a/Modules/_sre.c b/Modules/_sre.c
index 1b77416..979e61f 100644
--- a/Modules/_sre.c
+++ b/Modules/_sre.c
@@ -2683,6 +2683,12 @@
if (Py_TYPE(lefto) != &Pattern_Type || Py_TYPE(righto) != &Pattern_Type) {
Py_RETURN_NOTIMPLEMENTED;
}
+
+ if (lefto == righto) {
+ /* a pattern is equal to itself */
+ return PyBool_FromLong(op == Py_EQ);
+ }
+
left = (PatternObject *)lefto;
right = (PatternObject *)righto;