--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Tue Mar 22 19:34:47 2016 -0700
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/comp/Attr.java	Wed Mar 23 13:39:15 2016 +0100
@@ -282,7 +282,9 @@
      *  @param env    The current environment.
      */
     void checkAssignable(DiagnosticPosition pos, VarSymbol v, JCTree base, Env<AttrContext> env) {
-        if ((v.flags() & FINAL) != 0 &&
+        if (v.name == names._this) {
+            log.error(pos, Errors.CantAssignValToThis);
+        } else if ((v.flags() & FINAL) != 0 &&
             ((v.flags() & HASINIT) != 0
              ||
              !((base == null ||

--- a/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties	Tue Mar 22 19:34:47 2016 -0700
+++ b/langtools/src/jdk.compiler/share/classes/com/sun/tools/javac/resources/compiler.properties	Wed Mar 23 13:39:15 2016 +0100
@@ -274,6 +274,9 @@
 compiler.err.cant.assign.val.to.final.var=\
     cannot assign a value to final variable {0}
 
+compiler.err.cant.assign.val.to.this=\
+    cannot assign to ''this''
+
 # 0: symbol, 1: message segment
 compiler.err.cant.ref.non.effectively.final.var=\
     local variables referenced from {1} must be final or effectively final

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/tools/javac/diags/examples/CantAssignToThis.java	Wed Mar 23 13:39:15 2016 +0100
@@ -0,0 +1,30 @@
+/*
+ * 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.
+ *
+ * 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.
+ */
+
+// key: compiler.err.cant.assign.val.to.this
+
+class CantAssignToThis {
+    void m() {
+        this = null;
+    }
+}