manifest: add test for long hashes

manifest: add test for long hashes

Differential Revision: https://phab.mercurial-scm.org/D8373

--- a/tests/test-manifest.py	Thu Apr 02 16:24:34 2020 -0400
+++ b/tests/test-manifest.py	Wed Jan 08 11:33:01 2020 -0500
@@ -88,6 +88,10 @@
         with self.assertRaises(KeyError):
             m[b'wat']
 
+    def testManifestLongHashes(self):
+        m = self.parsemanifest(b'a\0' + b'f' * 64 + b'\n')
+        self.assertEqual(binascii.unhexlify(b'f' * 64), m[b'a'])
+
     def testSetItem(self):
         want = BIN_HASH_1