1 files changed, 57 insertions, 0 deletions
diff --git a/Lib/test/test_zlib.py b/Lib/test/test_zlib.py
index 7634680..ccbc8fd 100644
--- a/Lib/test/test_zlib.py
+++ b/Lib/test/test_zlib.py
@@ -302,6 +302,63 @@ class CompressObjectTestCase(unittest.TestCase):
         dco = zlib.decompressobj()
         self.assertEqual(dco.flush(), "") # Returns nothing
 
+    def test_compresscopy(self):
+        # Test copying a compression object
+        data0 = HAMLET_SCENE
+        data1 = HAMLET_SCENE.swapcase()
+        c0 = zlib.compressobj(zlib.Z_BEST_COMPRESSION)
+        bufs0 = []
+        bufs0.append(c0.compress(data0))
+
+        c1 = c0.copy()
+        bufs1 = bufs0[:]
+
+        bufs0.append(c0.compress(data0))
+        bufs0.append(c0.flush())
+        s0 = ''.join(bufs0)
+
+        bufs1.append(c1.compress(data1))
+        bufs1.append(c1.flush())
+        s1 = ''.join(bufs1)
+
+        self.assertEqual(zlib.decompress(s0),data0+data0)
+        self.assertEqual(zlib.decompress(s1),data0+data1)
+
+    def test_badcompresscopy(self):
+        # Test copying a compression object in an inconsistent state
+        c = zlib.compressobj()
+        c.compress(HAMLET_SCENE)
+        c.flush()
+        self.assertRaises(ValueError, c.copy)
+
+    def test_decompresscopy(self):
+        # Test copying a decompression object
+        data = HAMLET_SCENE
+        comp = zlib.compress(data)
+
+        d0 = zlib.decompressobj()
+        bufs0 = []
+        bufs0.append(d0.decompress(comp[:32]))
+
+        d1 = d0.copy()
+        bufs1 = bufs0[:]
+
+        bufs0.append(d0.decompress(comp[32:]))
+        s0 = ''.join(bufs0)
+
+        bufs1.append(d1.decompress(comp[32:]))
+        s1 = ''.join(bufs1)
+
+        self.assertEqual(s0,s1)
+        self.assertEqual(s0,data)
+
+    def test_baddecompresscopy(self):
+        # Test copying a compression object in an inconsistent state
+        data = zlib.compress(HAMLET_SCENE)
+        d = zlib.decompressobj()
+        d.decompress(data)
+        d.flush()
+        self.assertRaises(ValueError, d.copy)
 
 def genblock(seed, length, step=1024, generator=random):
     """length-byte stream of random data from a seed (in step-byte blocks)."""