Handle presence of index.jelly differently

src/it/missing-index-and-description/invoker.properties

@@ -0,0 +1,21 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+invoker.goals=-ntp clean package
+invoker.buildResult=failure

src/it/missing-index-and-description/pom.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>org.jenkins-ci.plugins</groupId>
+        <artifactId>plugin</artifactId>
+        <version>4.40</version>
+        <relativePath />
+    </parent>
+    <groupId>org.jenkins-ci.tools.hpi.its</groupId>
+    <artifactId>missing-index-and-description</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>hpi</packaging>
+    <name>MyNewPlugin</name>
+    <properties>
+        <jenkins.version>2.249.1</jenkins.version>
+        <hpi-plugin.version>@project.version@</hpi-plugin.version>
+    </properties>
+</project>

src/it/missing-index-and-description/src/main/java/org/jenkinsci/tools/hpi/its/X.java

@@ -0,0 +1,2 @@
+package org.jenkinsci.tools.hpi.its;
+public class X {}

src/it/missing-index-and-description/verify.groovy

@@ -0,0 +1,22 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+assert new File(basedir, 'build.log').getText('UTF-8').contains("Create src/main/resources/index.jelly:");
+
+return true;

src/it/missing-index/pom.xml

@@ -12,7 +12,7 @@
     <version>1.0-SNAPSHOT</version>
     <packaging>hpi</packaging>
     <name>MyNewPlugin</name>
-    <description>Deprecated spot for plugin description.</description>
+    <description>Deprecated spot for plugin "description" with &lt;4 special chars.</description>
     <properties>
         <jenkins.version>2.249.1</jenkins.version>
         <hpi-plugin.version>@project.version@</hpi-plugin.version>

src/it/missing-index/verify.groovy

@@ -17,6 +17,6 @@
  * under the License.
  */
 
-assert new File(basedir, 'build.log').getText('UTF-8').contains("create src/main/resources/index.jelly:");
+assert new File(basedir, 'build.log').getText('UTF-8').contains("A default one will be created using the description of the pom.xml");
 
 return true;

src/main/java/org/jenkinsci/maven/plugins/hpi/HpiMojo.java

@@ -18,7 +18,12 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.io.FileOutputStream;
+import java.io.OutputStreamWriter;
+import java.nio.charset.StandardCharsets;
 import java.util.Objects;
+
+import org.apache.commons.lang.StringEscapeUtils;
 import org.apache.maven.archiver.MavenArchiveConfiguration;
 import org.apache.maven.archiver.MavenArchiver;
 import org.apache.maven.artifact.Artifact;
@@ -30,6 +35,7 @@
 import org.apache.maven.plugins.annotations.Mojo;
 import org.apache.maven.plugins.annotations.Parameter;
 import org.apache.maven.plugins.annotations.ResolutionScope;
+import org.apache.maven.project.MavenProject;
 import org.codehaus.plexus.archiver.Archiver;
 import org.codehaus.plexus.archiver.ArchiverException;
 import org.codehaus.plexus.archiver.jar.JarArchiver;
@@ -136,11 +142,24 @@ private void performPackaging()
             jarArchiver.addConfiguredManifest(manifest);
             File indexJelly = new File(getClassesDirectory(), "index.jelly");
             if (!indexJelly.isFile()) {
-                throw new MojoFailureException("Missing " + indexJelly + ". Delete any <description> from pom.xml and create src/main/resources/index.jelly:\n" +
-                    "<?jelly escape-by-default='true'?>\n" +
-                    "<div>\n" +
-                    "    The description here…\n" +
-                    "</div>");
+                final String projectDescription = getProjectDescription();
+                if (projectDescription != null) {
+                    getLog().warn("src/main/resources/index.jelly does not exist. A default one will be created using the description of the pom.xml");
+                    try (final FileOutputStream fos = new FileOutputStream(indexJelly);
+                         final OutputStreamWriter indexJellyWriter = new OutputStreamWriter(fos, StandardCharsets.UTF_8)) {
+                        indexJellyWriter.write("<?jelly escape-by-default='true'?>\n" +
+                                "<div>\n" +
+                                StringEscapeUtils.escapeXml(projectDescription) + "\n" +
+                                "</div>");
+                        indexJellyWriter.flush();
+                    }
+                } else {
+                    throw new MojoFailureException("Missing " + indexJelly + ". Create src/main/resources/index.jelly:\n" +
+                            "<?jelly escape-by-default='true'?>\n" +
+                            "<div>\n" +
+                            "    The description here…\n" +
+                            "</div>");
+                }
             }
             jarArchiver.addDirectory(getClassesDirectory());
             archiver.createArchive(session, project, archive);
@@ -174,4 +193,43 @@ private void performPackaging()
 
     }
 
+    /**
+     * When calling {@code project.getDescription()}, it may return the description set in the parent project. What we
+     * want is the effective description defined in the project's pom.xml and not an inherited value.
+     *
+     * This method checks the project's description and if a value is found, compares it to the parent's one. In case
+     * they are the same, we consider this project has no description.
+     *
+     * @return The effective project's description or {@code null} if none or inherited from parent.
+     */
+    private String getProjectDescription() {
+        String description = project.getDescription();
+        if (description != null) {
+            description = description.trim();
+        } else {
+            return null;
+        }
+
+        if (description.isEmpty()) {
+            return null;
+        }
+
+        final MavenProject parent = project.getParent();
+        if (parent == null) {
+            // Should not happen as a Jenkins plugin should have a parent.
+            getLog().debug("When getting the project description, it seems the project has no parent");
+            return description;
+        }
+
+        String parentDescription = parent.getDescription();
+        if (parentDescription != null) {
+            parentDescription = parentDescription.trim();
+        }
+
+        if (description.equals(parentDescription)) {
+            return null;
+        }
+
+        return description;
+    }
 }