Issue #8672: Add a zlib test ensuring that an incomplete stream can be

handled by a decompressor object without errors (it returns incomplete
uncompressed data).

Lib/test/test_zlib.py

@@ -361,6 +361,19 @@ def test_empty_flush(self):
         dco = zlib.decompressobj()
         self.assertEqual(dco.flush(), "") # Returns nothing
 
+    def test_decompress_incomplete_stream(self):
+        # This is 'foo', deflated
+        x = 'x\x9cK\xcb\xcf\x07\x00\x02\x82\x01E'
+        # For the record
+        self.assertEqual(zlib.decompress(x), 'foo')
+        self.assertRaises(zlib.error, zlib.decompress, x[:-5])
+        # Omitting the stream end works with decompressor objects
+        # (see issue #8672).
+        dco = zlib.decompressobj()
+        y = dco.decompress(x[:-5])
+        y += dco.flush()
+        self.assertEqual(y, 'foo')
+
     if hasattr(zlib.compressobj(), "copy"):
         def test_compresscopy(self):
             # Test copying a compression object

Misc/NEWS

@@ -216,6 +216,10 @@ Extension Modules
 Tests
 -----
 
+- Issue #8672: Add a zlib test ensuring that an incomplete stream can be
+  handled by a decompressor object without errors (it returns incomplete
+  uncompressed data).
+
 - Issue #8490: asyncore now has a more solid test suite which actually tests 
   its API.