--- a/langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/util/Utils.java	Wed Feb 15 09:50:26 2017 -0800
+++ b/langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/util/Utils.java	Wed Feb 15 11:23:52 2017 -0800
@@ -1886,11 +1886,6 @@
             }
 
             @Override
-            public String visitPrimitive(PrimitiveType t, Void p) {
-                return t.toString();
-            }
-
-            @Override
             public String visitTypeVariable(javax.lang.model.type.TypeVariable t, Void p) {
                 // The knee jerk reaction is to do this but don't!, as we would like
                 // it to be compatible with the old world, now if we decide to do so
@@ -1900,9 +1895,10 @@
             }
 
             @Override
-            protected String defaultAction(TypeMirror e, Void p) {
-                throw new UnsupportedOperationException("should not happen");
+            protected String defaultAction(TypeMirror t, Void p) {
+                return t.toString();
             }
+
         }.visit(t);
     }
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/jdk/javadoc/doclet/testMissingType/TestMissingType.java	Wed Feb 15 11:23:52 2017 -0800
@@ -0,0 +1,50 @@
+/*
+ * 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.
+ */
+
+/*
+ * @test
+ * @bug      8173804
+ * @summary  make sure doclet can handle missing types
+ * @library  ../lib
+ * @modules jdk.javadoc/jdk.javadoc.internal.tool
+ * @build    JavadocTester
+ * @run main TestMissingType
+ */
+
+public class TestMissingType extends JavadocTester {
+
+    public static void main(String... args) throws Exception {
+        TestMissingType tester = new TestMissingType();
+        tester.runTests();
+    }
+
+    @Test
+    void test() {
+        javadoc("-d", "out",
+                "-use",
+                "-sourcepath", testSrc,
+                "p");
+        checkExit(Exit.OK);
+        checkFiles(true, "p/class-use/MissingType.html");
+    }
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/jdk/javadoc/doclet/testMissingType/p/MissingType.java	Wed Feb 15 11:23:52 2017 -0800
@@ -0,0 +1,32 @@
+/*
+ * 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 p;
+
+public final class MissingType  {
+    /**
+     * Do something with a missing type.
+     *
+     * @param out use the missing type
+     */
+    public void encode(MissingMe out) {}
+}