[JENKINS-20857] - add unit test which recreates NullPointerException if...

[JENKINS-20857] - add unit test which recreates NullPointerException if selected build has been deleted

test/src/test/java/hudson/model/RunParameterDefinitionTest.java

@@ -236,6 +236,30 @@ public class RunParameterDefinitionTest {
     }
     
     
+    @Test
+    public void testLoadEnvironmentVariablesWhenRunParameterJobHasBeenDeleted() throws Exception {
+
+        FreeStyleProject project = j.createFreeStyleProject("project");
+        FreeStyleBuild successfulBuild = project.scheduleBuild2(0).get();
+
+        FreeStyleProject paramProject = j.createFreeStyleProject("paramProject");
+        ParametersDefinitionProperty pdp =
+                new ParametersDefinitionProperty(new RunParameterDefinition("RUN",
+                                                                             project.getName(),
+                                                                             "run description",
+                                                                             RunParameterFilter.ALL));
+        paramProject.addProperty(pdp);
+
+        FreeStyleBuild build = paramProject.scheduleBuild2(0).get();
+        assertEquals(Integer.toString(project.getLastBuild().getNumber()),
+                     build.getEnvironment(new LogTaskListener(LOGGER, Level.INFO)).get("RUN_NUMBER"));
+
+        successfulBuild.delete();
+        // We should still be able to retrieve non RunParameter environment variables for the parameterized build
+        // even when the selected RunParameter build has been deleted.
+        assertEquals("paramProject", build.getEnvironment(new LogTaskListener(LOGGER, Level.INFO)).get("JOB_NAME"));
+    }
+
     static class ResultPublisher extends Publisher {
 
         private final Result result;