[FIXED JENKINS-18898] ToolInstallation.getHome may be null, and buildEnvVars...

[FIXED JENKINS-18898] ToolInstallation.getHome may be null, and buildEnvVars must take that into account.

changelog.html

@@ -67,6 +67,9 @@ Upcoming changes</a>
   <li class=bug>
     Provided maven settings.xml in maven builder is lost.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-15976">issue 15976</a>)
+  <li class=bug>
+    Exception when running polling with a Maven installation not defined on master.
+    (<a href="https://issues.jenkins-ci.org/browse/JENKINS-18898">issue 18898</a>)
   <li class=bug>
     Since 1.477 GET on <code>/view/…/config.xml</code> included a spurious wrapper element.
     (<a href="https://issues.jenkins-ci.org/browse/JENKINS-17302">issue 17302</a>)

core/src/main/java/hudson/model/JDK.java

@@ -105,9 +105,13 @@ public final class JDK extends ToolInstallation implements NodeSpecific<JDK>, En
      * @deprecated as of 1.460. Use {@link #buildEnvVars(EnvVars)}
      */
     public void buildEnvVars(Map<String,String> env) {
+        String home = getHome();
+        if (home == null) {
+            return;
+        }
         // see EnvVars javadoc for why this adds PATH.
-        env.put("PATH+JDK",getHome()+"/bin");
-        env.put("JAVA_HOME",getHome());
+        env.put("PATH+JDK",home+"/bin");
+        env.put("JAVA_HOME", home);
     }
 
     /**

core/src/main/java/hudson/tasks/Maven.java

@@ -486,6 +486,9 @@ public class Maven extends Builder {
         @Override
         public void buildEnvVars(EnvVars env) {
             String home = getHome();
+            if (home == null) {
+                return;
+            }
             env.put("M2_HOME", home);
             env.put("MAVEN_HOME", home);
             env.put("PATH+MAVEN", home + "/bin");

core/src/main/java/hudson/tools/ToolInstallation.java

@@ -32,7 +32,6 @@ import hudson.diagnosis.OldDataMonitor;
 import hudson.model.*;
 import hudson.slaves.NodeSpecific;
 import hudson.util.DescribableList;
-import hudson.util.StreamTaskListener;
 import hudson.util.XStream2;
 
 import java.io.Serializable;
@@ -41,6 +40,7 @@ import java.util.List;
 
 import com.thoughtworks.xstream.annotations.XStreamSerializable;
 import com.thoughtworks.xstream.converters.UnmarshallingContext;
+import javax.annotation.CheckForNull;
 import jenkins.model.Jenkins;
 
 /**
@@ -125,8 +125,9 @@ public abstract class ToolInstallation extends AbstractDescribableImpl<ToolInsta
      * 
      * The path can be in Unix format as well as in Windows format.
      * Must be absolute.
+     * @return the home directory location, if defined (may only be defined on the result of {@link #translate(Node, EnvVars, TaskListener)}, e.g. if unavailable on master)
      */
-    public String getHome() {
+    public @CheckForNull String getHome() {
         return home;
     }
 

test/src/test/java/hudson/tasks/MavenTest.java

@@ -64,8 +64,10 @@ import org.jvnet.hudson.test.HudsonTestCase;
 import com.gargoylesoftware.htmlunit.html.HtmlForm;
 import com.gargoylesoftware.htmlunit.html.HtmlPage;
 import com.gargoylesoftware.htmlunit.html.HtmlButton;
+import hudson.EnvVars;
 import hudson.model.FreeStyleBuild;
 import hudson.model.PasswordParameterDefinition;
+import org.jvnet.hudson.test.Bug;
 import org.jvnet.hudson.test.ExtractResourceSCM;
 import org.jvnet.hudson.test.SingleFileSCM;
 import org.jvnet.hudson.test.TestExtension;
@@ -237,4 +239,12 @@ public class MavenTest extends HudsonTestCase {
             assertEquals("/tmp/global-settigns.xml", ((FilePathGlobalSettingsProvider)m.getGlobalSettings()).getPath());
         }
     }
+
+    @Bug(18898)
+    public void testNullHome() throws Exception {
+        EnvVars env = new EnvVars();
+        new MavenInstallation("_", "", Collections.<ToolProperty<?>>emptyList()).buildEnvVars(env);
+        assertEquals("{}", env.toString());
+    }
+
 }