--- /dev/null	2017-03-16 11:03:49.895616831 -0700
+++ new/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.core.test/src/org/graalvm/compiler/core/test/ea/PartialEscapeAnalysisTreesTest.java	2017-08-03 22:42:58.700785272 -0700
@@ -0,0 +1,136 @@
+/*
+ * Copyright (c) 2017, Oracle and/or its affiliates. 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.
+ */
+package org.graalvm.compiler.core.test.ea;
+
+import java.util.HashSet;
+
+import org.graalvm.compiler.api.directives.GraalDirectives;
+import org.graalvm.compiler.core.test.GraalCompilerTest;
+import org.graalvm.compiler.debug.DebugContext;
+import org.graalvm.compiler.nodes.debug.BlackholeNode;
+import org.graalvm.compiler.phases.common.CanonicalizerPhase;
+import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;
+import org.junit.Assert;
+import org.junit.Test;
+
+import jdk.vm.ci.code.InstalledCode;
+import jdk.vm.ci.meta.ResolvedJavaMethod;
+
+/*
+ * Test whether complex tree structures properly maintain identity.
+ */
+public class PartialEscapeAnalysisTreesTest extends EATestBase {
+
+    static class TreeNode {
+        TreeNode left;
+        TreeNode right;
+
+        TreeNode() {
+
+        }
+
+        TreeNode(TreeNode left, TreeNode right) {
+            this.left = left;
+            this.right = right;
+        }
+
+        public void visit(HashSet<TreeNode> instances) {
+            instances.add(this);
+            if (left != null) {
+                left.visit(instances);
+            }
+            if (right != null) {
+                right.visit(instances);
+            }
+        }
+
+        int countInstances() {
+            HashSet<TreeNode> instances = new HashSet<>();
+            visit(instances);
+            return instances.size();
+        }
+    }
+
+    public static TreeNode buildTree(boolean a) {
+        TreeNode leftChild;
+        TreeNode rightChild;
+        TreeNode taskToFork;
+        TreeNode task;
+        if (a) {
+            GraalDirectives.blackhole(new TreeNode());
+            leftChild = new TreeNode();
+            rightChild = new TreeNode();
+            task = new TreeNode(leftChild, rightChild);
+            taskToFork = rightChild;
+            GraalDirectives.blackhole(task);
+        } else {
+            leftChild = new TreeNode();
+            rightChild = new TreeNode();
+            task = new TreeNode(leftChild, rightChild);
+            taskToFork = leftChild;
+            GraalDirectives.blackhole(task);
+        }
+        if (taskToFork.left == null) {
+            taskToFork.left = new TreeNode();
+        }
+
+        return new TreeNode(task, null);
+    }
+
+    @Test
+    public void testBuildTree() {
+        testGraph("buildTree");
+    }
+
+    /**
+     * Prepare a graph that includes some blackholes and then remove the blackholes and compile
+     * normally to create an unusual situation for PEA.
+     */
+    @SuppressWarnings("try")
+    public void testGraph(String name) {
+        ResolvedJavaMethod method = getResolvedJavaMethod(name);
+
+        prepareGraph(name, true);
+        try (DebugContext.Scope s = graph.getDebug().scope(getClass(), method, getCodeCache(), graph)) {
+            for (BlackholeNode node : graph.getNodes().filter(BlackholeNode.class)) {
+                graph.removeFixed(node);
+            }
+            new DeadCodeEliminationPhase().apply(graph);
+            new CanonicalizerPhase().apply(graph, context);
+
+            InstalledCode code = getCode(method, graph, true);
+
+            GraalCompilerTest.Result r = executeExpected(method, null, true);
+            int expectedInstances = ((TreeNode) r.returnValue).countInstances();
+            TreeNode r2 = (TreeNode) code.executeVarargs(true);
+            Assert.assertEquals("Wrong number of nodes in tree", expectedInstances, r2.countInstances());
+
+            r = executeExpected(method, null, false);
+            expectedInstances = ((TreeNode) r.returnValue).countInstances();
+            r2 = (TreeNode) code.executeVarargs(false);
+            Assert.assertEquals("Wrong number of nodes in tree", expectedInstances, r2.countInstances());
+        } catch (Throwable e) {
+            throw graph.getDebug().handle(e);
+        }
+    }
+}