Avoid UnicodeDecodeError when query string is unicode

Fixes PYTHON-76

CHANGELOG.rst

@@ -35,6 +35,7 @@ Bug Fixes
 * Fix cassandra.concurrent behavior when dealing with automatic paging
   (PYTHON-81)
 * Properly defunct connections after protocol errors
+* Avoid UnicodeDecodeError when query string is unicode (PYTHON-76)
 
 2.0.2
 =====

cassandra/cluster.py

@@ -1253,8 +1253,10 @@ class Session(object):
 
         if isinstance(query, SimpleStatement):
             query_string = query.query_string
+            if six.PY2 and isinstance(query_string, six.text_type):
+                query_string = query_string.encode('utf-8')
             if parameters:
-                query_string = bind_params(query.query_string, parameters, self.encoders)
+                query_string = bind_params(query_string, parameters, self.encoders)
             message = QueryMessage(
                 query_string, cl, query.serial_consistency_level,
                 fetch_size, timestamp=timestamp)

tests/integration/standard/test_types.py

@@ -436,3 +436,10 @@ class TypeTests(unittest.TestCase):
         prepared = s.prepare("SELECT b FROM mytable WHERE a=?")
         self.assertEqual(complete, s.execute(prepared, (2,))[0].b)
         self.assertEqual(partial_result, s.execute(prepared, (3,))[0].b)
+
+    def test_unicode_query_string(self):
+        c = Cluster(protocol_version=PROTOCOL_VERSION)
+        s = c.connect()
+
+        query = u"SELECT * FROM system.schema_columnfamilies WHERE keyspace_name = 'ef\u2052ef' AND columnfamily_name = %s"
+        s.execute(query, (u"fe\u2051fe",))