[FIXED JENKINS-48209] Prevent serialization of when expression closure

This shouldn't really matter, in truth - I believe we actually
regenerate the whole Root object from scratch on resume, though I
could be misremembering. Regardless, even having the when expression
closure be transient, the durability test (with when expressions
added) still works right.

As to why we need to do this in the first place? Because something
weird could be out there trying to some non-standard serialization of
Describables. Ok, spoiler, there definitely is such a thing, and it
does a straight XStream serialization of every Describable. But we use
Describables as more than just UI config stuff - we use them for
syntax validation and such for our internal extension points, like
when conditions. And if that XStream serialization of a when
expression with a sh step kicks in, well, all hell breaks loose. This
works around that.

pipeline-model-definition/src/main/groovy/org/jenkinsci/plugins/pipeline/modeldefinition/parser/ASTParserUtils.groovy

@@ -180,6 +180,23 @@ class ASTParserUtils {
             s << printer(" - op: ${n.operation.toString()}", ind)
             s << printer("  - right:", ind)
             s << prettyPrint(n.rightExpression, ind)
+        } else if (n instanceof IfStatement) {
+            s << printer("- if stmt:", ind)
+            s << prettyPrint(n.booleanExpression, ind)
+            s << printer("- if block:", ind)
+            s << prettyPrint(n.ifBlock, ind)
+            if (n.elseBlock != null) {
+                s << printer("- else block:", ind)
+                s << prettyPrint(n.elseBlock, ind )
+            }
+        } else if (n instanceof TupleExpression) {
+            s << printer("- tuples:", ind)
+            n.expressions.each {
+                s << prettyPrint(it, ind)
+            }
+        } else if (n instanceof BooleanExpression) {
+            s << printer("- boolexp:", ind)
+            s << prettyPrint(n.expression, ind)
         } else {
             s << printer("- ${n}", ind)
         }

pipeline-model-definition/src/main/java/org/jenkinsci/plugins/pipeline/modeldefinition/when/impl/ExpressionConditional.java

@@ -50,7 +50,8 @@
 public class ExpressionConditional extends DeclarativeStageConditional<ExpressionConditional> {
     private final String block;
 
-    private Closure closureBlock;
+    // Needs to be transient to avoid potential excessive pickling - see JENKINS-48209
+    private transient Closure closureBlock;
 
     @Deprecated
     public ExpressionConditional(String block) {

pipeline-model-definition/src/test/java/org/jenkinsci/plugins/pipeline/modeldefinition/DurabilityTest.java

@@ -113,10 +113,25 @@ public void survivesRestart() throws Exception {
                                 "      }\n" +
                                 "    }\n" +
                                 "    stage('bar') {\n" +
+                                "      when {\n" +
+                                "        expression {\n" +
+                                "          return true\n" +
+                                "        }\n" +
+                                "      }\n" +
                                 "      steps {\n" +
                                 "        sh('echo reallyAfterFoo')\n" +
                                 "      }\n" +
                                 "    }\n" +
+                                "    stage('baz') {\n" +
+                                "      when {\n" +
+                                "        expression {\n" +
+                                "          return false\n" +
+                                "        }\n" +
+                                "      }\n" +
+                                "      steps {\n" +
+                                "        sh('echo neverShouldReach')\n" +
+                                "      }\n" +
+                                "    }\n" +
                                 "  }\n" +
                                 "}",
                         true));
@@ -135,6 +150,7 @@ public void survivesRestart() throws Exception {
                 story.j.assertLogContains("before=demo", b);
                 story.j.assertLogContains("ONAGENT=true", b);
                 story.j.assertLogContains("reallyAfterFoo", b);
+                story.j.assertLogNotContains("neverShouldReach", b);
                 FlowExecution execution = b.getExecution();
                 assertNotNull(execution);
                 FlowGraphWalker walker = new FlowGraphWalker(execution);

pipeline-model-definition/src/test/java/org/jenkinsci/plugins/pipeline/modeldefinition/WhenStageTest.java

@@ -40,9 +40,13 @@
 import org.jenkinsci.plugins.pipeline.modeldefinition.endpoints.ModelConverterAction;
 import org.jenkinsci.plugins.pipeline.modeldefinition.model.Stage;
 import org.jenkinsci.plugins.pipeline.modeldefinition.when.ChangeLogStrategy;
+import org.jenkinsci.plugins.pipeline.modeldefinition.when.DeclarativeStageConditional;
 import org.jenkinsci.plugins.workflow.job.WorkflowJob;
 import org.jenkinsci.plugins.workflow.job.WorkflowRun;
 import org.jenkinsci.plugins.workflow.multibranch.WorkflowMultiBranchProject;
+import org.jenkinsci.plugins.workflow.pickles.Pickle;
+import org.jenkinsci.plugins.workflow.support.pickles.SingleTypedPickleFactory;
+import org.jenkinsci.plugins.workflow.support.pickles.XStreamPickle;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.jvnet.hudson.test.Issue;
@@ -357,6 +361,14 @@ public void whenChangelogPR() throws Exception {
 
     }
 
+    @Issue("JENKINS-48209")
+    @Test
+    public void whenExprDurableTask() throws Exception {
+        expect("whenExprDurableTask")
+                .logContains("Heal it")
+                .go();
+    }
+
     private void waitFor(Queue.Item item) throws InterruptedException, ExecutionException {
         while (item != null && item.getFuture() == null) {
             Thread.sleep(200);
@@ -386,4 +398,14 @@ protected boolean shouldExamineAllBuilds(@Nonnull SCMHead head) {
             return false;
         }
     }
+
+    @TestExtension
+    public static class WhenConditionPickleFactory extends SingleTypedPickleFactory<DeclarativeStageConditional<?>> {
+        @Override
+        @Nonnull
+        protected Pickle pickle(DeclarativeStageConditional<?> d) {
+            return new XStreamPickle(d);
+        }
+    }
+
 }

pipeline-model-definition/src/test/resources/whenExprDurableTask.groovy

@@ -0,0 +1,55 @@
+/*
+ * The MIT License
+ *
+ * Copyright (c) 2017, CloudBees, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+pipeline {
+    agent {
+        label "here"
+    }
+
+    stages {
+        stage("One") {
+            steps {
+                echo "Hello"
+            }
+        }
+        stage("Two") {
+            when {
+                expression {
+                    if (isUnix()) {
+                        return sh(script: "echo true", returnStdout: true).trim() == "true"
+                    } else {
+                        return bat(script: "echo true", returnStdout: true).trim() == "true"
+                    }
+                }
+            }
+            steps {
+                script {
+                    echo "World"
+                    echo "Heal it"
+                }
+
+            }
+        }
+    }
+}