[MNG-7642] Restore compatibility with flatten-maven-plugin (#947)

Revert "[MNG-7505] Remove ReportingConverter (#906)"
This reverts commit adf89ef63f.

maven-model-builder/src/main/java/org/apache/maven/model/building/DefaultModelBuilder.java

@@ -76,6 +76,7 @@
 import org.apache.maven.model.plugin.LifecycleBindingsInjector;
 import org.apache.maven.model.plugin.PluginConfigurationExpander;
 import org.apache.maven.model.plugin.ReportConfigurationExpander;
+import org.apache.maven.model.plugin.ReportingConverter;
 import org.apache.maven.model.profile.DefaultProfileActivationContext;
 import org.apache.maven.model.profile.ProfileActivationContext;
 import org.apache.maven.model.profile.ProfileInjector;
@@ -625,6 +626,15 @@ public DefaultModelBuilder setProfileActivationFilePathInterpolator(
                 versionProcessor);
     }
 
+    /**
+     * @deprecated since Maven 4
+     * @see DefaultModelBuilderFactory#setReportingConverter(ReportingConverter)
+     */
+    @Deprecated
+    public DefaultModelBuilder setReportingConverter(ReportingConverter reportingConverter) {
+        return this;
+    }
+
     @Override
     public DefaultTransformerContextBuilder newTransformerContextBuilder() {
         return new DefaultTransformerContextBuilder();

maven-model-builder/src/main/java/org/apache/maven/model/building/DefaultModelBuilderFactory.java

@@ -50,9 +50,11 @@
 import org.apache.maven.model.path.UrlNormalizer;
 import org.apache.maven.model.plugin.DefaultPluginConfigurationExpander;
 import org.apache.maven.model.plugin.DefaultReportConfigurationExpander;
+import org.apache.maven.model.plugin.DefaultReportingConverter;
 import org.apache.maven.model.plugin.LifecycleBindingsInjector;
 import org.apache.maven.model.plugin.PluginConfigurationExpander;
 import org.apache.maven.model.plugin.ReportConfigurationExpander;
+import org.apache.maven.model.plugin.ReportingConverter;
 import org.apache.maven.model.profile.DefaultProfileInjector;
 import org.apache.maven.model.profile.DefaultProfileSelector;
 import org.apache.maven.model.profile.ProfileInjector;
@@ -183,6 +185,11 @@ public DefaultModelBuilderFactory setReportConfigurationExpander(
         return this;
     }
 
+    @Deprecated
+    public DefaultModelBuilderFactory setReportingConverter(ReportingConverter reportingConverter) {
+        return this;
+    }
+
     public DefaultModelBuilderFactory setProfileActivationFilePathInterpolator(
             ProfileActivationFilePathInterpolator profileActivationFilePathInterpolator) {
         this.profileActivationFilePathInterpolator = profileActivationFilePathInterpolator;
@@ -294,6 +301,11 @@ protected ReportConfigurationExpander newReportConfigurationExpander() {
         return new DefaultReportConfigurationExpander();
     }
 
+    @Deprecated
+    protected ReportingConverter newReportingConverter() {
+        return new DefaultReportingConverter();
+    }
+
     private ModelSourceTransformer newModelSourceTransformer() {
         return new DefaultModelSourceTransformer();
     }

maven-model-builder/src/main/java/org/apache/maven/model/plugin/DefaultReportingConverter.java

@@ -0,0 +1,42 @@
+/*
+ * 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.
+ */
+package org.apache.maven.model.plugin;
+
+import javax.inject.Named;
+import javax.inject.Singleton;
+
+import org.apache.maven.model.Model;
+import org.apache.maven.model.building.ModelBuildingRequest;
+import org.apache.maven.model.building.ModelProblemCollector;
+
+/**
+ * Handles conversion of the <code>&lt;reporting&gt;</code> section into the configuration of Maven Site Plugin 3.x,
+ * i.e. <code>reportPlugins</code> and <code>outputDirectory</code> parameters.
+ *
+ * @author Benjamin Bentmann
+ * @deprecated since maven 4.0, this class is now a no-op class and is only here for compatibility
+ */
+@Named
+@Singleton
+@Deprecated
+public class DefaultReportingConverter implements ReportingConverter {
+
+    @Override
+    public void convertReporting(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {}
+}

maven-model-builder/src/main/java/org/apache/maven/model/plugin/ReportingConverter.java

@@ -0,0 +1,43 @@
+/*
+ * 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.
+ */
+package org.apache.maven.model.plugin;
+
+import org.apache.maven.model.Model;
+import org.apache.maven.model.building.ModelBuildingRequest;
+import org.apache.maven.model.building.ModelProblemCollector;
+
+/**
+ * Handles conversion of the <code>&lt;reporting&gt;</code> section into the configuration of Maven Site Plugin 3.x,
+ * i.e. <code>reportPlugins</code> and <code>outputDirectory</code> parameters.
+ *
+ * @author Benjamin Bentmann
+ * @deprecated since maven 4.0, this interface is not used anymore and is only here for compatibility
+ */
+@Deprecated
+public interface ReportingConverter {
+
+    /**
+     * Converts values from model's reporting section into the configuration for Maven Site Plugin 3.x.
+     *
+     * @param model The model whose reporting section should be converted, must not be <code>null</code>.
+     * @param request The model building request that holds further settings, must not be {@code null}.
+     * @param problems The container used to collect problems that were encountered, must not be {@code null}.
+     */
+    void convertReporting(Model model, ModelBuildingRequest request, ModelProblemCollector problems);
+}