Bug #1586613: fix zlib and bz2 codecs' incremental en/decoders.
 (backport from rev. 52529)
diff --git a/Lib/test/test_codecs.py b/Lib/test/test_codecs.py
index 60b8a72..e64e781 100644
--- a/Lib/test/test_codecs.py
+++ b/Lib/test/test_codecs.py
@@ -1063,6 +1063,7 @@
     "punycode",
     "unicode_internal"
 ]
+broken_incremental_coders = broken_unicode_with_streams[:]
 
 try:
     import bz2
@@ -1112,6 +1113,7 @@
                     decodedresult += reader.read()
                 self.assertEqual(decodedresult, s, "%r != %r (encoding=%r)" % (decodedresult, s, encoding))
 
+            if encoding not in broken_incremental_coders:
                 # check incremental decoder/encoder (fetched via the Python
                 # and C API) and iterencode()/iterdecode()
                 try: