[JENKINS-26137] At least during restarting tests, serialization error…

…s seem to be due to there being no PickleFactory’s installed.

Merely calling PickleFactory.all() from the RiverWriter constructor, rather than later, seems to let PushdStepTest.restarting pass (JENKINS-26051).
Additionally asserting that there are in fact some factories loaded, since there is sure to be trouble if there are not.
Also need to wait for the build to finish (JENKINS-26399).

aggregator/src/test/java/org/jenkinsci/plugins/workflow/steps/PushdStepTest.java

@@ -28,7 +28,6 @@
 import org.jenkinsci.plugins.workflow.job.WorkflowJob;
 import org.jenkinsci.plugins.workflow.job.WorkflowRun;
 import org.jenkinsci.plugins.workflow.test.steps.SemaphoreStep;
-import org.junit.Ignore;
 import org.junit.Test;
 import org.junit.Rule;
 import org.junit.runners.model.Statement;
@@ -48,7 +47,6 @@
         });
     }
 
-    @Ignore("TODO as per JENKINS-26149 PushdStep.Execution.step might need to be optional=true, but cannot get this test to pass because of JENKINS-26137")
     @Test public void restarting() {
         story.addStep(new Statement() {
             @Override public void evaluate() throws Throwable {
@@ -62,6 +60,9 @@
             @Override public void evaluate() throws Throwable {
                 SemaphoreStep.success("restarting/1", null);
                 WorkflowRun b = story.j.jenkins.getItemByFullName("p", WorkflowJob.class).getLastBuild();
+                while (b.isBuilding()) { // TODO JENKINS-26399
+                    Thread.sleep(100);
+                }
                 story.j.assertLogContains("/subdir", story.j.assertBuildStatusSuccess(b));
             }
         });

support/src/main/java/org/jenkinsci/plugins/workflow/support/pickles/serialization/RiverWriter.java

@@ -28,6 +28,7 @@
 import org.jenkinsci.plugins.workflow.pickles.Pickle;
 import org.jenkinsci.plugins.workflow.pickles.PickleFactory;
 import com.trilead.ssh2.util.IOUtils;
+import hudson.ExtensionList;
 import org.jboss.marshalling.Marshaller;
 import org.jboss.marshalling.Marshalling;
 import org.jboss.marshalling.MarshallingConfiguration;
@@ -87,6 +88,10 @@
 
     // TODO: rename to HibernatingObjectOutputStream?
     public RiverWriter(File f, FlowExecutionOwner _owner) throws IOException {
+        final ExtensionList<PickleFactory> pickleFactories = PickleFactory.all();
+        if (pickleFactories.isEmpty()) {
+            throw new IllegalStateException("JENKINS-26137: Jenkins is shutting down");
+        }
         file = f;
         owner = _owner;
         dout = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file)));
@@ -107,7 +112,7 @@ public Object writeReplace(Object o) {
                     return new DryOwner();
 
                 if (pickling) {
-                    for (PickleFactory f : PickleFactory.all()) {
+                    for (PickleFactory f : pickleFactories) {
                         Pickle v = f.writeReplace(o);
                         if (v != null) {
                             pickles.add(v);