1 files changed, 14 insertions, 1 deletions
diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index f084ebeadd..54de508a83 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -931,7 +931,7 @@ class TestBasicOpsString(TestBasicOps, unittest.TestCase):
 
 class TestBasicOpsBytes(TestBasicOps, unittest.TestCase):
     def setUp(self):
-        self.case   = "string set"
+        self.case   = "bytes set"
         self.values = [b"a", b"b", b"c"]
         self.set    = set(self.values)
         self.dup    = set(self.values)
@@ -1742,6 +1742,19 @@ class TestWeirdBugs(unittest.TestCase):
         s.update(range(100))
         list(si)
 
+    def test_merge_and_mutate(self):
+        class X:
+            def __hash__(self):
+                return hash(0)
+            def __eq__(self, o):
+                other.clear()
+                return False
+
+        other = set()
+        other = {X() for i in range(10)}
+        s = {0}
+        s.update(other)
+
 # Application tests (based on David Eppstein's graph recipes ====================================
 
 def powerset(U):