[FIXED JENKINS-31386] Define the scm var in standalone projects using…

… CpsScmFlowDefinition.

CHANGES.md

@@ -2,6 +2,10 @@
 
 Only noting significant user changes, not internal code cleanups and minor bug fixes.
 
+## 1.12 (upcoming)
+
+* [JENKINS-31386](https://issues.jenkins-ci.org/browse/JENKINS-31386): `checkout scm` now works also in _Workflow script from SCM_ to better interoperate with multibranch projects.
+
 ## 1.12-beta-2 (Nov 25 2015)
 
 * [JENKINS-29705](https://issues.jenkins-ci.org/browse/JENKINS-29705): added _Thread Dump_ link to running flow builds for diagnosing problems like hangs.

cps/src/main/resources/org/jenkinsci/plugins/workflow/cps/CpsScmFlowDefinition/config.jelly

@@ -27,7 +27,7 @@ THE SOFTWARE.
 <j:jelly xmlns:j="jelly:core" xmlns:f="/lib/form" xmlns:st="jelly:stapler">
     <f:dropdownDescriptorSelector field="scm" title="SCM" descriptors="${descriptor.applicableDescriptors}"/>
     <f:entry field="scriptPath" title="${%Script Path}">
-        <f:textbox default="flow.groovy"/>
+        <f:textbox default="Jenkinsfile"/>
     </f:entry>
     <st:include it="${descriptor.snippetizer}" page="block.jelly"/>
 </j:jelly>

cps/src/main/resources/org/jenkinsci/plugins/workflow/cps/CpsScmFlowDefinition/help-scriptPath.html

@@ -1,4 +1,6 @@
 <div>
     Relative location within the checkout of your Workflow script.
     Note that it will always be run inside a Groovy sandbox.
+    <code>Jenkinsfile</code> is conventional and allows you to switch easily to a multibranch project
+    (just use <code>checkout scm</code> to retrieve sources from the same location as is configured here).
 </div>

multibranch/src/main/java/org/jenkinsci/plugins/workflow/multibranch/SCMVar.java

@@ -36,8 +36,11 @@
 import jenkins.branch.Branch;
 import jenkins.scm.api.SCMRevisionAction;
 import jenkins.scm.api.SCMSource;
+import org.jenkinsci.plugins.workflow.cps.CpsScmFlowDefinition;
 import org.jenkinsci.plugins.workflow.cps.CpsScript;
 import org.jenkinsci.plugins.workflow.cps.GlobalVariable;
+import org.jenkinsci.plugins.workflow.flow.FlowDefinition;
+import org.jenkinsci.plugins.workflow.job.WorkflowJob;
 import org.jenkinsci.plugins.workflow.job.WorkflowRun;
 import org.jenkinsci.plugins.workflow.pickles.Pickle;
 import org.jenkinsci.plugins.workflow.support.pickles.SingleTypedPickleFactory;
@@ -62,6 +65,13 @@
         Job<?,?> job = build.getParent();
         BranchJobProperty property = job.getProperty(BranchJobProperty.class);
         if (property == null) {
+            if (job instanceof WorkflowJob) {
+                FlowDefinition defn = ((WorkflowJob) job).getDefinition();
+                if (defn instanceof CpsScmFlowDefinition) {
+                    // JENKINS-31386: retrofit to work with standalone projects, minus the exact revision support.
+                    return ((CpsScmFlowDefinition) defn).getScm();
+                }
+            }
             throw new IllegalStateException("inappropriate context");
         }
         Branch branch = property.getBranch();

multibranch/src/main/resources/org/jenkinsci/plugins/workflow/multibranch/SCMVar/help.jelly

@@ -27,4 +27,7 @@ THE SOFTWARE.
 <j:jelly xmlns:j="jelly:core">
     Represents the SCM configuration in a multibranch project build.
     Use <code>checkout scm</code> to check out sources matching <code>Jenkinsfile</code>.
+    <br/>You may also use this in a standalone project configured with <i>Workflow script from SCM</i>,
+    though in that case the checkout will just be of the latest revision in the branch,
+    possibly newer than the revision from which the Workflow script was loaded.
 </j:jelly>

multibranch/src/test/java/org/jenkinsci/plugins/workflow/multibranch/SCMVarTest.java

@@ -33,10 +33,12 @@
 import jenkins.plugins.git.GitSCMSource;
 import org.apache.commons.io.FileUtils;
 import org.jenkinsci.plugins.scriptsecurity.scripts.ScriptApproval;
+import org.jenkinsci.plugins.workflow.cps.CpsScmFlowDefinition;
 import org.jenkinsci.plugins.workflow.cps.global.WorkflowLibRepository;
 import org.jenkinsci.plugins.workflow.job.WorkflowJob;
 import org.jenkinsci.plugins.workflow.job.WorkflowRun;
 import org.jenkinsci.plugins.workflow.steps.scm.GitSampleRepoRule;
+import org.jenkinsci.plugins.workflow.steps.scm.GitStep;
 import org.jenkinsci.plugins.workflow.test.steps.SemaphoreStep;
 import org.junit.Test;
 import static org.junit.Assert.*;
@@ -121,4 +123,21 @@ public class SCMVarTest {
         });
     }
 
+    @Issue("JENKINS-31386")
+    @Test public void standaloneProject() {
+        story.addStep(new Statement() {
+            @Override public void evaluate() throws Throwable {
+                sampleGitRepo.init();
+                sampleGitRepo.write("Jenkinsfile", "node {checkout scm; echo readFile('file')}");
+                sampleGitRepo.write("file", "some content");
+                sampleGitRepo.git("add", "Jenkinsfile");
+                sampleGitRepo.git("commit", "--all", "--message=flow");
+                WorkflowJob p = story.j.jenkins.createProject(WorkflowJob.class, "p");
+                p.setDefinition(new CpsScmFlowDefinition(new GitStep(sampleGitRepo.toString()).createSCM(), "Jenkinsfile"));
+                WorkflowRun b = story.j.assertBuildStatusSuccess(p.scheduleBuild2(0));
+                story.j.assertLogContains("some content", b);
+            }
+        });
+    }
+
 }