--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/sjavac/comp/SjavacImpl.java	Wed Mar 02 12:54:56 2016 +0100
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/sjavac/comp/SjavacImpl.java	Wed Mar 02 13:12:24 2016 +0100
@@ -28,7 +28,6 @@
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
-import java.io.Writer;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -81,6 +80,10 @@
         if (!validateOptions(options))
             return RC_FATAL;
 
+        if (srcDstOverlap(options.getSources(), options.getDestDir())) {
+            return RC_FATAL;
+        }
+
         if (!createIfMissing(options.getDestDir()))
             return RC_FATAL;
 
@@ -330,6 +333,22 @@
 
     }
 
+    private static boolean srcDstOverlap(List<SourceLocation> locs, Path dest) {
+        for (SourceLocation loc : locs) {
+            if (isOverlapping(loc.getPath(), dest)) {
+                Log.error("Source location " + loc.getPath() + " overlaps with destination " + dest);
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static boolean isOverlapping(Path p1, Path p2) {
+        p1 = p1.toAbsolutePath().normalize();
+        p2 = p2.toAbsolutePath().normalize();
+        return p1.startsWith(p2) || p2.startsWith(p1);
+    }
+
     private static boolean createIfMissing(Path dir) {
 
         if (Files.isDirectory(dir))

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/sjavac/OverlappingSrcDst.java	Wed Mar 02 13:12:24 2016 +0100
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2016, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+
+/*
+ * @test
+ * @summary Make sure sjavac doesn't allow overlapping source and destination
+ *          directories.
+ * @bug 8061320
+ * @library /tools/lib
+ * @modules jdk.compiler/com.sun.tools.javac.api
+ *          jdk.compiler/com.sun.tools.javac.file
+ *          jdk.compiler/com.sun.tools.javac.main
+ *          jdk.compiler/com.sun.tools.sjavac
+ * @build Wrapper ToolBox
+ * @run main Wrapper OverlappingSrcDst
+ */
+
+import java.io.File;
+import java.nio.file.Paths;
+
+public class OverlappingSrcDst extends SJavacTester {
+    public static void main(String... args) {
+        new OverlappingSrcDst().run();
+    }
+
+    public void run() {
+        String abs = ToolBox.currDir.toAbsolutePath().toString();
+
+        // Relative vs relative
+        test("dir", "dir", false);
+        test("dir", "dir/dst", false);
+        test("dir/src", "dir", false);
+        test("src", "dst", true);
+
+        // Absolute vs absolute
+        test(abs + "/dir", abs + "/dir", false);
+        test(abs + "/dir", abs + "/dir/dst", false);
+        test(abs + "/dir/src", abs + "/dir", false);
+        test(abs + "/src", abs + "/dst", true);
+
+        // Absolute vs relative
+        test(abs + "/dir", "dir", false);
+        test(abs + "/dir", "dir/dst", false);
+        test(abs + "/dir/src", "dir", false);
+        test(abs + "/src", "dst", true);
+
+        // Relative vs absolute
+        test("dir", abs + "/dir", false);
+        test("dir", abs + "/dir/dst", false);
+        test("dir/src", abs + "/dir", false);
+        test("src", abs + "/dst", true);
+    }
+
+    private void test(String srcDir, String dstDir, boolean shouldSucceed) {
+        boolean succeeded = testCompilation(srcDir, dstDir);
+        if (shouldSucceed != succeeded) {
+            throw new AssertionError(
+                    String.format("Test failed for "
+                                          + "srcDir=\"%s\", "
+                                          + "dstDir=\"%s\". "
+                                          + "Compilation was expected to %s but %s.",
+                                  srcDir,
+                                  dstDir,
+                                  shouldSucceed ? "succeed" : "fail",
+                                  succeeded ? "succeeded" : "failed"));
+        }
+    }
+
+    private boolean testCompilation(String srcDir, String dstDir) {
+        try {
+            srcDir = srcDir.replace('/', File.separatorChar);
+            dstDir = dstDir.replace('/', File.separatorChar);
+            tb.writeFile(Paths.get(srcDir, "pkg", "A.java"), "package pkg; class A {}");
+            compile("--state-dir=state", "-src", srcDir, "-d", dstDir);
+            return true;
+        } catch (Exception e) {
+            return false;
+        }
+    }
+}