Prevent NPE when checking for a re-runnable continued flow, remove usage of

state transition comparator in FlowParser, ensure custom exit code is set at
job level.

Fixes TCK test testDeciderExitStatusIsSetOnJobContext, contributes but does
not fix decider transition tests that include restart.

spring-batch-core/src/test/java/org/springframework/batch/core/jsr/step/DecisionStepTests.java

@@ -86,6 +86,19 @@ public class DecisionStepTests {
 		}
 	}
 
+	@Test
+	public void testDecisionCustomExitStatus() throws Exception {
+		ApplicationContext context = new GenericXmlApplicationContext("classpath:/org/springframework/batch/core/jsr/step/DecisionStepTests-decisionCustomExitStatus-context.xml");
+
+		JobLauncher launcher = context.getBean(JobLauncher.class);
+		Job job = context.getBean(Job.class);
+
+		JobExecution execution = launcher.run(job, new JobParameters());
+		assertEquals(BatchStatus.FAILED, execution.getStatus());
+		assertEquals(2, execution.getStepExecutions().size());
+		assertEquals("CustomFail", execution.getExitStatus().getExitCode());
+	}
+
 	@Test
 	@Ignore("Flows as first steps are not supported yet")
 	public void testDecisionAfterFlow() throws Exception {
@@ -108,6 +121,12 @@ public class DecisionStepTests {
 
 		@Override
 		public String decide(StepExecution[] executions) throws Exception {
+			for(StepExecution stepExecution : executions) {
+				if ("customFailTest".equals(stepExecution.getStepName())) {
+					return "CustomFail";
+				}
+			}
+
 			return "next";
 		}
 	}