8170825: Generated index page has a broken link

Reviewed-by: jjg

langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/SplitIndexWriter.java

@@ -107,12 +107,16 @@ public class SplitIndexWriter extends AbstractIndexWriter {
         Set<Character> keys = new TreeSet<>(indexbuilder.getIndexMap().keySet());
         keys.addAll(configuration.tagSearchIndexKeys);
         ListIterator<Character> li = new ArrayList<>(keys).listIterator();
+        int prev;
+        int next;
         while (li.hasNext()) {
+            prev = (li.hasPrevious()) ? li.previousIndex() + 1 : -1;
             Object ch = li.next();
+            next = (li.hasNext()) ? li.nextIndex() + 1 : -1;
             DocPath filename = DocPaths.indexN(li.nextIndex());
             SplitIndexWriter indexgen = new SplitIndexWriter(configuration,
                     path.resolve(filename),
-                    indexbuilder, keys, li.previousIndex(), li.nextIndex());
+                    indexbuilder, keys, prev, next);
             indexgen.generateIndexFile((Character) ch);
             if (!li.hasNext()) {
                 indexgen.createSearchIndexFiles();

langtools/test/jdk/javadoc/doclet/testIndexFiles/TestIndexFiles.java

@@ -0,0 +1,64 @@
+/*
+ * 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      8170825
+ * @summary  Perform tests on index files generated by javadoc.
+ * @author   bpatel
+ * @library  ../lib
+ * @modules jdk.javadoc/jdk.javadoc.internal.tool
+ * @build    JavadocTester
+ * @run main TestIndexFiles
+ */
+
+public class TestIndexFiles extends JavadocTester {
+
+    public static void main(String... args) throws Exception {
+        TestIndexFiles tester = new TestIndexFiles();
+        tester.runTests();
+    }
+
+    @Test
+    void testIndexFiles() {
+        javadoc("-d", "out", "-splitindex", "-Xdoclint:none", "-sourcepath", testSrc,
+                "-use", "pkg");
+        checkExit(Exit.OK);
+        checkIndexFiles(true);
+    }
+
+    void checkIndexFiles(boolean found) {
+        checkOutput("index-files/index-1.html", found,
+                "<li>Prev Letter</li>\n"
+                + "<li><a href=\"index-2.html\">Next Letter</a></li>");
+        checkOutput("index-files/index-5.html", found,
+                "<li><a href=\"index-4.html\">Prev Letter</a></li>\n"
+                + "<li>Next Letter</li>");
+        checkOutput("index-files/index-1.html", !found,
+                "<li><a href=\"index-0.html\">Prev Letter</a></li>\n"
+                + "<li><a href=\"index-1.html\">Next Letter</a></li>");
+        checkOutput("index-files/index-5.html", !found,
+                "<li><a href=\"index-4.html\">Prev Letter</a></li>\n"
+                + "<li><a href=\"index-5.html\">Next Letter</a></li>");
+    }
+}

langtools/test/jdk/javadoc/doclet/testIndexFiles/pkg/ClassForIndexFilesTest.java

@@ -0,0 +1,45 @@
+/*
+ * 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 pkg;
+
+public class ClassForIndexFilesTest {
+
+    /**
+     * Test field.
+     */
+    public int field1;
+
+    /**
+     * Test method.
+     */
+    public void testMethod() {
+    }
+
+    /**
+     * Another test method.
+     */
+    public void anotherTestMethod() {
+    }
+
+}

langtools/test/jdk/javadoc/doclet/testIndexFiles/pkg/package-info.java

@@ -0,0 +1,27 @@
+/*
+ * 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 pkg used for testing index files.
+ */
+package pkg;