--- /dev/null	2020-09-04 12:37:41.765504620 +0200
+++ new/test/hotspot/gtest/metaspace/test_allocationGuard.cpp	2020-09-04 13:58:15.869525164 +0200
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020 SAP SE. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+
+#include "memory/metaspace/msArena.hpp"
+#include "memory/metaspace/msTestHelpers.hpp"
+#include "memory/metaspace/msSettings.hpp"
+
+//#define LOG_PLEASE
+#include "metaspaceGtestCommon.hpp"
+#include "metaspaceGtestContexts.hpp"
+
+#ifdef ASSERT
+
+using metaspace::MetaspaceArena;
+using metaspace::MetaspaceTestArena;
+using metaspace::Settings;
+
+
+// Test that overwriting memory triggers an assert if allocation guards are enabled.
+//  Note: We use TEST_VM_ASSERT_MSG. However, an assert is only triggered if allocation
+//  guards are enabled; if guards are disabled for the gtests, this test would fail.
+//  So for that case, we trigger a fake assert.
+TEST_VM_ASSERT_MSG(metaspace, test_overwriter, "Corrupt block") {
+
+  if (Settings::use_allocation_guard()) {
+    MetaspaceGtestContext context;
+    MetaspaceTestArena* arena = context.create_arena(Metaspace::StandardMetaspaceType);
+    MetaWord* p = arena->allocate(10);
+    MetaWord* p2 = arena->allocate(10);
+    p[10] = (MetaWord)0x9345; // Overwriter
+    // Checks should run in destructor:
+    delete arena;
+  } else {
+    assert(false, "Corrupt block fake message to satisfy tests");
+  }
+
+}
+
+#endif // ASSERT