Issue #11109: Avoid NPE using ProjectId (#11178)

Co-authored-by: Vincent Potucek <vpotucek@me.com>

Author: Pankraz76

impl/maven-core/src/main/java/org/apache/maven/project/collector/DefaultProjectsSelector.java

@@ -75,7 +75,7 @@ public List<MavenProject> selectProjects(List<File> files, MavenExecutionRequest
                         "{} {} encountered while building the effective model for '{}' (use -e to see details)",
                         problemsCount,
                         (problemsCount == 1) ? "problem was" : "problems were",
-                        result.getProject().getId());
+                        result.getProjectId());
 
                 if (request.isShowErrors()) { // this means -e or -X (as -X enables -e as well)
                     for (ModelProblem problem : result.getProblems()) {

its/core-it-suite/src/test/resources/mng-5208/spy/src/main/java/mng5208/EventLoggerSpy.java

@@ -34,8 +34,7 @@ public void onEvent(Object event) throws Exception {
         if (event instanceof ExecutionEvent) {
 
             ExecutionEvent executionEvent = (ExecutionEvent) event;
-            System.out.println("executionEvent:" + executionEvent.getType() + "/"
-                    + executionEvent.getProject().getId());
+            System.out.println("executionEvent:" + executionEvent.getType() + "/" + executionEvent.getProjectId());
         }
     }
 }