--- a/langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/ModuleWriterImpl.java	Wed Mar 15 11:42:42 2017 +0000
+++ b/langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/ModuleWriterImpl.java	Wed Mar 15 06:30:33 2017 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 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
@@ -25,6 +25,7 @@
 
 package jdk.javadoc.internal.doclets.formats.html;
 
+import java.util.Collections;
 import java.util.EnumSet;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -284,12 +285,14 @@
                 additionalModules.remove(m);
         }
         });
+
         // Get all packages for the module and put it in the concealed packages set.
-        (utils.getModulePackageMap().get(mdle)).forEach((pkg) -> {
+        utils.getModulePackageMap().getOrDefault(mdle, Collections.emptySet()).forEach((pkg) -> {
             if (shouldDocument(pkg)) {
                 concealedPackages.add(pkg);
             }
         });
+
         // Get all exported packages for the module using the exports directive for the module.
         (ElementFilter.exportsIn(mdle.getDirectives())).forEach((directive) -> {
             PackageElement p = directive.getPackage();

--- a/langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/Configuration.java	Wed Mar 15 11:42:42 2017 +0000
+++ b/langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/toolkit/Configuration.java	Wed Mar 15 06:30:33 2017 -0700
@@ -441,6 +441,11 @@
             }
         }
 
+        // add entries for modules which may not have exported packages
+        modules.forEach((ModuleElement mdle) -> {
+            modulePackages.computeIfAbsent(mdle, m -> Collections.emptySet());
+        });
+
         modules.addAll(modulePackages.keySet());
         showModules = !modules.isEmpty();
         for (Set<PackageElement> pkgs : modulePackages.values()) {

--- a/langtools/test/jdk/javadoc/doclet/testModules/TestModules.java	Wed Mar 15 11:42:42 2017 +0000
+++ b/langtools/test/jdk/javadoc/doclet/testModules/TestModules.java	Wed Mar 15 06:30:33 2017 -0700
@@ -24,7 +24,7 @@
 /*
  * @test
  * @bug 8154119 8154262 8156077 8157987 8154261 8154817 8135291 8155995 8162363
- *      8168766 8168688 8162674 8160196 8175799 8174974
+ *      8168766 8168688 8162674 8160196 8175799 8174974 8176778
  * @summary Test modules support in javadoc.
  * @author bpatel
  * @library ../lib
@@ -182,6 +182,19 @@
     }
 
     /**
+     * Test generated module summary page of an aggregating module.
+     */
+    @Test
+    void testAggregatorModuleSummary() {
+        javadoc("-d", "out-aggregatorModuleSummary", "-use",
+                "--module-source-path", testSrc,
+                "--expand-requires", "transitive",
+                "--module", "moduleT");
+        checkExit(Exit.OK);
+        checkAggregatorModuleSummary();
+    }
+
+    /**
      * Test generated module pages and pages with link to modules.
      */
     @Test
@@ -599,6 +612,32 @@
                 + "</tr>");
     }
 
+    void checkAggregatorModuleSummary() {
+        checkOutput("moduleT-summary.html", true,
+                "<div class=\"header\">\n"
+                + "<h1 title=\"Module\" class=\"title\">Module&nbsp;moduleT</h1>\n"
+                + "</div>",
+                "<div class=\"block\">This is a test description for the moduleT module. "
+                + "Search phrase <a id=\"searchphrase\">search phrase</a>. "
+                + "Make sure there are no exported packages.</div>",
+                "<tbody>\n"
+                + "<tr class=\"altColor\">\n"
+                + "<td class=\"colFirst\">transitive</td>\n"
+                + "<th class=\"colSecond\" scope=\"row\"><a href=\"moduleA-summary.html\">moduleA</a></th>\n"
+                + "<td class=\"colLast\">\n"
+                + "<div class=\"block\">This is a test description for the moduleA module.</div>\n"
+                + "</td>\n"
+                + "</tr>\n"
+                + "<tr class=\"rowColor\">\n"
+                + "<td class=\"colFirst\">transitive</td>\n"
+                + "<th class=\"colSecond\" scope=\"row\"><a href=\"moduleB-summary.html\">moduleB</a></th>\n"
+                + "<td class=\"colLast\">\n"
+                + "<div class=\"block\">This is a test description for the moduleB module.</div>\n"
+                + "</td>\n"
+                + "</tr>\n"
+                + "</tbody>");
+    }
+
     void checkNegatedModuleSummary() {
         checkOutput("moduleA-summary.html", false,
                 "<!-- ============ SERVICES SUMMARY =========== -->\n"

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/test/jdk/javadoc/doclet/testModules/moduleT/module-info.java	Wed Mar 15 06:30:33 2017 -0700
@@ -0,0 +1,33 @@
+/*
+ * 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.  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.
+ */
+
+/**
+  * This is a test description for the moduleT module. Search phrase {@index "search phrase" with description}. Make sure there are no exported packages.
+  *
+  */
+module moduleT {
+    requires transitive moduleA;
+    requires transitive moduleB;
+}