Add OK packet processing test

Added a test case which exercises the OK packet handling in
readwritesplit.

maxscale-system-test/large_insert_hang.cpp

@@ -0,0 +1,28 @@
+/**
+ * Check that the OK packet flags are read correctly
+ */
+
+#include "testconnections.h"
+
+int main(int argc, char *argv[])
+{
+    TestConnections test(argc, argv);
+    test.set_timeout(60);
+
+    test.connect_maxscale();
+    test.try_query(test.conn_rwsplit, "CREATE OR REPLACE TABLE test.t1(id int)");
+
+    std::stringstream ss;
+    ss << "INSERT INTO test.t1 VALUES (0)";
+
+    for (int i = 0; i < 2299; i++)
+    {
+        ss << ",(" << i << ")";
+    }
+
+    test.try_query(test.conn_rwsplit, query.str().c_str());
+    test.try_query(test.conn_rwsplit, "DROP TABLE test.t1");
+    test.close_maxscale_connections();
+
+    return test.global_result;
+}