Issue 6573: Fix set.union() for cases where self is in the argument chain.
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index 15d3c6f..222726c 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -82,6 +82,10 @@
self.assertEqual(self.thetype('abcba').union(C('ef')), set('abcef'))
self.assertEqual(self.thetype('abcba').union(C('ef'), C('fg')), set('abcefg'))
+ # Issue #6573
+ x = self.thetype()
+ self.assertEqual(x.union(set([1]), x, set([2])), self.thetype([1, 2]))
+
def test_or(self):
i = self.s.union(self.otherword)
self.assertEqual(self.s | set(self.otherword), i)
diff --git a/Misc/NEWS b/Misc/NEWS
index cca4d76..a882c9c 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -14,6 +14,9 @@
- Issue #6540: Fixed crash for bytearray.translate() with invalid parameters.
+- Issue #6573: set.union() stopped processing inputs if an instance of self
+ occurred in the argument chain.
+
- Issue #6070: On posix platforms import no longer copies the execute bit
from the .py file to the .pyc file if it is set.
diff --git a/Objects/setobject.c b/Objects/setobject.c
index 8ecc405..b296f9f 100644
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -1187,7 +1187,7 @@
for (i=0 ; i<PyTuple_GET_SIZE(args) ; i++) {
other = PyTuple_GET_ITEM(args, i);
if ((PyObject *)so == other)
- return (PyObject *)result;
+ continue;
if (set_update_internal(result, other) == -1) {
Py_DECREF(result);
return NULL;