[MINVOKER-374] Ability to skip project collection (#265)

Author: gnodet

Diff for: src/main/java/org/apache/maven/plugins/invoker/AbstractInvokerMojo.java

@@ -695,6 +695,18 @@ public abstract class AbstractInvokerMojo extends AbstractMojo {
     @Parameter(defaultValue = "false", property = "invoker.updateSnapshots")
     private boolean updateSnapshots;
 
+    /**
+     * Projects that are cloned undergo some filtering. In order to grab all projects and make sure
+     * they are all filtered, projects are read and parsed. In some cases, this may not be a desired
+     * behavior (especially when some pom.xml cannot be parsed by Maven directly).  In such cases,
+     * the exact list of projects can be set using this field, avoiding the parsing of all pom.xml
+     * files found.
+     *
+     * @since 3.9.0
+     */
+    @Parameter
+    private List<String> collectedProjects;
+
     // internal state variables
 
     /**
@@ -802,11 +814,6 @@ public void execute() throws MojoExecutionException, MojoFailureException {
 
         handleScriptRunnerWithScriptClassPath();
 
-        Collection<String> collectedProjects = new LinkedHashSet<>();
-        for (BuildJob buildJob : buildJobs) {
-            collectProjects(projectsDirectory, buildJob.getProject(), collectedProjects, true);
-        }
-
         File projectsDir = projectsDirectory;
 
         if (cloneProjectsTo == null && "maven-plugin".equals(project.getPackaging())) {
@@ -826,6 +833,13 @@ public void execute() throws MojoExecutionException, MojoFailureException {
         }
 
         if (cloneProjectsTo != null) {
+            Collection<String> collectedProjects = this.collectedProjects;
+            if (collectedProjects == null) {
+                collectedProjects = new LinkedHashSet<>();
+                for (BuildJob buildJob : buildJobs) {
+                    collectProjects(projectsDirectory, buildJob.getProject(), collectedProjects, true);
+                }
+            }
             cloneProjects(collectedProjects);
             addMissingDotMvnDirectory(cloneProjectsTo, buildJobs);
             projectsDir = cloneProjectsTo;
@@ -1088,7 +1102,7 @@ private boolean isNotEmpty(String s) {
      *
      * @param projectPaths The paths to the projects to clone, relative to the projects directory, must not be
      *            <code>null</code> nor contain <code>null</code> elements.
-     * @throws org.apache.maven.plugin.MojoExecutionException If the the projects could not be copied/filtered.
+     * @throws org.apache.maven.plugin.MojoExecutionException If the projects could not be copied/filtered.
      */
     private void cloneProjects(Collection<String> projectPaths) throws MojoExecutionException {
         if (!cloneProjectsTo.mkdirs() && cloneClean) {