Warn when 'Check out to a sub-directory' is used with Pipeline jobs (fixes #3068)

src/main/java/hudson/plugins/git/extensions/impl/RelativeTargetDirectory.java

@@ -38,6 +38,10 @@
         if (relativeTargetDir == null || relativeTargetDir.length() == 0 || relativeTargetDir.equals(".")) {
             return workspace;
         }
+       //fixing issue : #3068 : Warn if used in Pipeline
+        if ( context != null && context.getClass().getName().equals("org.jenkinsci.plugins.workflow.job.WorkflowJob")){
+            listener.getLogger().println("[Warning] 'Check out to a sub-directory' is not intended for use with Pipeline jobs. Please use the 'dir' step instead. ");
+        }
         return workspace.child(environment.expand(relativeTargetDir));
     }
 

src/test/java/hudson/plugins/git/RelativeTargetDirectoryPipelineTest.java

@@ -0,0 +1,55 @@
+package hudson.plugins.git;
+
+import org.jenkinsci.plugins.workflow.cps.CpsFlowDefinition;
+import org.jenkinsci.plugins.workflow.job.WorkflowJob;
+import org.jenkinsci.plugins.workflow.job.WorkflowRun;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.AfterEach;
+import org.jvnet.hudson.test.JenkinsRule;
+import org.jvnet.hudson.test.junit.jupiter.WithJenkins;
+import jenkins.plugins.git.GitSampleRepoRule;
+
+@WithJenkins
+public class RelativeTargetDirectoryPipelineTest {
+
+    public GitSampleRepoRule sampleRepo = new GitSampleRepoRule();
+
+    @BeforeEach
+    public void setupRepo() throws Throwable {
+        sampleRepo.before();
+    }
+
+    @AfterEach
+    public void tearDownRepo() {
+        sampleRepo.after();
+    }
+
+    @Test
+    public void warningIsLoggedWhenUsedInPipeline(JenkinsRule j) throws Exception {
+        // 1. Init a git repo
+        sampleRepo.init();
+        sampleRepo.write("Jenkinsfile", "echo 'hello'");
+        sampleRepo.git("add", "Jenkinsfile");
+        sampleRepo.git("commit", "--all", "-m", "init");
+
+        // 2. Create Pipeline Job
+        WorkflowJob job = j.createProject(WorkflowJob.class, "test-job");
+        String repoUrl = sampleRepo.toString();
+
+        // 3. Script that uses the bad feature
+        String pipelineScript =
+                "node {\n" +
+                        "  checkout([$class: 'GitSCM',\n" +
+                        "    branches: [[name: '*/master']],\n" +
+                        "    userRemoteConfigs: [[url: '" + repoUrl + "']],\n" +
+                        "    extensions: [[$class: 'RelativeTargetDirectory', relativeTargetDir: 'subdir']]\n" +
+                        "  ])\n" +
+                        "}\n";
+        job.setDefinition(new CpsFlowDefinition(pipelineScript, true));
+
+        // 4. Run and Assert
+        WorkflowRun run = j.buildAndAssertSuccess(job);
+        j.assertLogContains("'Check out to a sub-directory' is not intended for use with Pipeline jobs", run);
+    }
+}