From 7fc344dc96008f277dacf5518b28447f3a598cde Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Hannes=20Walln=C3=B6fer?= <hannesw@openjdk.org>
Date: Mon, 15 Nov 2021 15:53:43 +0000
Subject: [PATCH] 8277028: Use service type documentation as fallback for
 @provides

Reviewed-by: prappo
---
 .../formats/html/ModuleWriterImpl.java        | 10 +++---
 .../testModules/TestModuleServices.java       | 33 +++++++++++++++++--
 2 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/ModuleWriterImpl.java b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/ModuleWriterImpl.java
index 878e1bd4920..e4dd2efd10d 100644
--- a/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/ModuleWriterImpl.java
+++ b/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/ModuleWriterImpl.java
@@ -763,12 +763,14 @@ public class ModuleWriterImpl extends HtmlDocletWriter implements ModuleSummaryW
             Content desc = new ContentBuilder();
             if (display(providesTrees)) {
                 description = providesTrees.get(srv);
-                desc.add((description != null && !description.isEmpty())
-                        ? HtmlTree.DIV(HtmlStyle.block, description)
-                        : Entity.NO_BREAK_SPACE);
+                if (description != null && !description.isEmpty()) {
+                    desc.add(HtmlTree.DIV(HtmlStyle.block, description));
+                } else {
+                    addSummaryComment(srv, desc);
+                }
             } else {
                 desc.add(Entity.NO_BREAK_SPACE);
-                }
+            }
             // Only display the implementation details in the "all" mode.
             if (moduleMode == ModuleMode.ALL && !implSet.isEmpty()) {
                 desc.add(new HtmlTree(TagName.BR));
diff --git a/test/langtools/jdk/javadoc/doclet/testModules/TestModuleServices.java b/test/langtools/jdk/javadoc/doclet/testModules/TestModuleServices.java
index a371a466945..ed965ee937d 100644
--- a/test/langtools/jdk/javadoc/doclet/testModules/TestModuleServices.java
+++ b/test/langtools/jdk/javadoc/doclet/testModules/TestModuleServices.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2021, 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
@@ -23,7 +23,7 @@
 
 /*
  * @test
- * @bug 8178067 8192007 8182765 8184205
+ * @bug 8178067 8192007 8182765 8184205 8277028
  * @summary tests the module's services, such as provides and uses
  * @modules jdk.javadoc/jdk.javadoc.internal.api
  *          jdk.javadoc/jdk.javadoc.internal.tool
@@ -93,6 +93,26 @@ public class TestModuleServices extends JavadocTester {
                         public void testMethod2() {}
                     }""");
         mb.write(src);
+        mb = new ModuleBuilder(tb, "moduleServiceProviderNoDescription")
+                .comment("""
+                    This is another module that provides an implementation of a service.
+                    @provides pkgService.Service""")
+                .requires("moduleService")
+                .provides("pkgService.Service", "pkgServiceProviderNoDesc.ServiceProviderNoDescription")
+                .classes("/**A Package that has a service provider.*/ package pkgServiceProviderNoDesc;")
+                .classes("""
+                    package pkgServiceProviderNoDesc;
+                    public class ServiceProviderNoDescription implements pkgService.Service {
+                        /**
+                         * {@inheritDoc}
+                         */
+                        public void testMethod1() {}
+                        /**
+                         * This is an internal implementation so the documentation will not be seen.
+                         */
+                        public void testMethod2() {}
+                    }""");
+        mb.write(src);
         mb = new ModuleBuilder(tb, "moduleServiceUser")
                 .comment("""
                     This module uses a service defined in another module.
@@ -128,7 +148,8 @@ public class TestModuleServices extends JavadocTester {
                 "-quiet",
                 "-noindex",
                 "--module-source-path", src.toString(),
-                "--module", "moduleService,moduleServiceProvider,moduleServiceUser,moduleServiceUserNoDescription",
+                "--module", "moduleService,moduleServiceProvider,moduleServiceProviderNoDescription",
+                "--module", "moduleServiceUser,moduleServiceUserNoDescription",
                 "pkgService", "moduleServiceProvider/pkgServiceProvider", "moduleServiceUser/pkgServiceUser",
                 "moduleServiceUserNoDescription/pkgServiceUserNoDescription");
         checkExit(Exit.OK);
@@ -139,6 +160,12 @@ public class TestModuleServices extends JavadocTester {
                     ml" title="interface in pkgService">Service</a></div>
                     <div class="col-last even-row-color">
                     <div class="block">Provides a service whose name is ServiceProvider.</div>""");
+        checkOutput("moduleServiceProviderNoDescription/module-summary.html", true,
+                """
+                    <div class="col-first even-row-color"><a href="../moduleService/pkgService/Service.ht\
+                    ml" title="interface in pkgService">Service</a></div>
+                    <div class="col-last even-row-color">
+                    <div class="block">A service Interface for service providers.</div>""");
         checkOutput("moduleServiceUser/module-summary.html", true,
                 """
                     <div class="col-first even-row-color"><a href="../moduleService/pkgService/Service.ht\