Fix for CONC-139:

When using binary protocol, convert data to binary object only if the
character set is BINARY (63), not if the flag was set.

mariadb/mariadb_codecs.c

@@ -785,8 +785,7 @@ field_fetch_callback(void *data, unsigned int column, unsigned char **row)
             unsigned long utf8len;
             length= mysql_net_field_length(row);
 
-            if ((self->fields[column].flags & BINARY_FLAG ||
-                self->fields[column].charsetnr == CHARSET_BINARY))
+            if (self->fields[column].charsetnr == CHARSET_BINARY)
             {
                 self->values[column]=
                         PyBytes_FromStringAndSize((const char *)*row,

mariadb/mariadb_connection.c

@@ -612,7 +612,8 @@ void MrdbConnection_dealloc(MrdbConnection *self)
             mysql_close(self->mysql);
             Py_END_ALLOW_THREADS
         }
-        Py_DECREF(self->server_version_info);
+        if (self->server_version_info)
+            Py_DECREF(self->server_version_info);
         Py_TYPE(self)->tp_free((PyObject*)self);
     }
 }

testing/test/integration/test_cursor.py

@@ -1135,6 +1135,23 @@ def test_conpy133(self):
             pass
         del cursor
 
+    def test_conpy139(self):
+        connection= create_connection()
+        cursor= connection.cursor()
+        cursor.execute("create temporary table t1 (a varchar(254) character set utf8mb4 collate utf8mb4_bin)")
+        cursor.execute("insert into t1 values ('foo')")
+        del cursor
+        c1= connection.cursor()
+        c2= connection.cursor(prepared=True)
+        c1.execute("select a from t1")
+        r1= c1.fetchall()
+        c2.execute("select a from t1")
+        r2= c2.fetchall()
+        self.assertEqual(r1, r2)
+
+        del c1, c2
+        connection.close()
+
     def test_conpy91(self):
         with create_connection() as connection:
             with connection.cursor() as cursor: