Test polling of parent of HEAD commit with and without workspace

More testing of JENKINS-29066

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

@@ -1429,28 +1429,45 @@ public void testPolling_environmentValueInBranchSpec() throws Exception {
     }
 
     @Issue("JENKINS-29066")
-    public void testPolling_parentHead() throws Exception {
+    public void baseTestPolling_parentHead(List<GitSCMExtension> extensions) throws Exception {
         // create parameterized project with environment value in branch specification
         FreeStyleProject project = createFreeStyleProject();
         GitSCM scm = new GitSCM(
                 createRemoteRepositories(),
                 Collections.singletonList(new BranchSpec("**")),
                 false, Collections.<SubmoduleConfig>emptyList(),
                 null, null,
-                Collections.<GitSCMExtension>emptyList());
+                extensions);
         project.setScm(scm);
 
         // commit something in order to create an initial base version in git
         commit("toto/commitFile1", johnDoe, "Commit number 1");
         git.branch("someBranch");
         commit("toto/commitFile2", johnDoe, "Commit number 2");
 
+        assertTrue("polling should detect changes",project.poll(listener).hasChanges());
+
         // build the project
         build(project, Result.SUCCESS);
 
+        /* Expects 1 build because the build of someBranch incorporates all
+         * the changes from the master branch as well as the changes from someBranch.
+         */
+        assertEquals("Wrong number of builds", 1, project.getBuilds().size());
+
         assertFalse("polling should not detect changes",project.poll(listener).hasChanges());
     }
 
+    @Issue("JENKINS-29066")
+    public void testPolling_parentHead() throws Exception {
+        baseTestPolling_parentHead(Collections.<GitSCMExtension>emptyList());
+    }
+
+    @Issue("JENKINS-29066")
+    public void testPolling_parentHead_DisableRemotePoll() throws Exception {
+        baseTestPolling_parentHead(Collections.<GitSCMExtension>singletonList(new DisableRemotePoll()));
+    }
+
     public void testPollingAfterManualBuildWithParametrizedBranchSpec() throws Exception {
         // create parameterized project with environment value in branch specification
         FreeStyleProject project = createFreeStyleProject();