<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>tests.project</groupId>
    <artifactId>duplicate-plugin-defs-merged</artifactId>
    <version>1</version>

    <build>
      <plugins>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <dependencies>
            <dependency>
              <groupId>group</groupId>
              <artifactId>first</artifactId>
              <version>1</version>

        }

        return new InputLocation(-1, -1, InputSource.merge(source.getSource(), target.getSource()), locations);
    } // -- InputLocation merge( InputLocation, InputLocation, boolean )

    /**
     * Merges the {@code source} location into the {@code target} location.
     * This method is used when the locations refer to lists and also merges the indices.
     *
     * @param target the target location

                    PluginExecution existing = merged.get(key);
                    if (existing != null) {
                        element = mergePluginExecution(existing, element, sourceDominant, context);
                    }
                    merged.put(key, element);
                }

                builder.executions(merged.values());
            }
        }

        @Override

        if (repositories != null) {
            Map<String, Server> serversById = new HashMap<>();

            if (servers != null) {
                for (Server server : servers) {
                    if (!serversById.containsKey(server.getId())) {
                        serversById.put(server.getId(), server);
                    }
                }

import org.apache.maven.api.services.model.*;

/**
 * Handles normalization of a model.
 *
 */
@Named
@Singleton
public class DefaultModelNormalizer implements ModelNormalizer {

    private DuplicateMerger merger = new DuplicateMerger();

    @Override
    public Model mergeDuplicates(Model model, ModelBuilderRequest request, ModelProblemCollector problems) {
        Model.Builder builder = Model.newBuilder(model);

  <artifactId>parent</artifactId>
  <version>0.1</version>
  <packaging>pom</packaging>

  <name>Maven Integration Test :: MNG-3916</name>
  <description>
    Test that plugin executions are properly merged during inheritance, even if the child plugin section has no
    version.
  </description>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.its.plugins</groupId>

    <version>0.1</version>
  </parent>

  <artifactId>child</artifactId>

  <name>Maven Integration Test :: MNG-3943</name>
  <description>
    Test that plugin executions are properly merged during inheritance, even if the child uses a different
    plugin version than the parent.
  </description>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.its.plugins</groupId>

    <version>0.1</version>
  </parent>

  <artifactId>child</artifactId>

  <name>Maven Integration Test :: MNG-3938</name>
  <description>
    Test that plugin executions with the same id are merged during inheritance, especially executions using the
    default id, regardless whether the id is given explicitly by the user or implicitly assumed from defaults.
  </description>

  <build>
    <plugins>
      <plugin>

  <artifactId>parent</artifactId>
  <version>1.0</version>
  <packaging>pom</packaging>

  <name>Maven Integration Test :: MNG-4008</name>
  <description>
    Verify that filter definitions are properly merged.
  </description>

  <build>
    <filters>
      <!-- NOTE: The first filter is deliberately defined by the child as well, so should not be added twice -->
      <filter>src/main/filters/child-a.properties</filter>

    <version>0.1</version>
  </parent>

  <artifactId>child</artifactId>

  <name>Maven Integration Test :: MNG-3906</name>
  <description>
    Test that project-level plugin dependencies are properly merged during inheritance.
  </description>

  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.its.plugins</groupId>
        <artifactId>maven-it-plugin-class-loader</artifactId>