Add test

tests/python/unittest/test_gluon.py

@@ -1511,6 +1511,35 @@ def forward(self, x):
     net2 = Network()
     net2.load_parameters('tmp.params')
 
+@with_seed()
+def test_save_load_with_shared_params():
+    class B(mx.gluon.Block):
+        def __init__(self, params=None):
+            super().__init__(params=params)
+
+            with self.name_scope():
+                self.weight = self.params.get('weight', shape=(10, 10))
+
+    class C(mx.gluon.Block):
+        def __init__(self, b1, b2):
+            super().__init__()
+            self.b1 = b1
+            self.b2 = b2
+
+    b1 = B()
+    b2 = B(b1.collect_params())
+    c = C(b1, b2)
+    c.initialize()
+    c.save_parameters('tmp.params')
+
+    params = mx.nd.load('tmp.params')
+    assert len(params) == 1  # Only a single copy of the shared parameter is saved
+
+    b1 = B()
+    b2 = B(b1.collect_params())
+    c = C(b1, b2)
+    c.load_parameters('tmp.params')
+
 @with_seed()
 def test_symbol_block_save_load():
     class Net(gluon.HybridBlock):