Copy missing Context keys from JobParameters

Fix DefaultJobParametersExtractor to copy values from JobParameters when
they are missing from ExecutionContext. Javadoc states this class is
supposed to do just that, but seems to have broken in the 5.x API revamp.

Resolves #4458

Author: jwillebrands

spring-batch-core/src/main/java/org/springframework/batch/core/step/job/DefaultJobParametersExtractor.java

@@ -79,6 +79,9 @@ public JobParameters getJobParameters(Job job, StepExecution stepExecution) {
 			if (executionContext.containsKey(key)) {
 				properties.setProperty(key, executionContext.getString(key));
 			}
+			else if (jobParameters.containsKey(key)) {
+				builder.addJobParameter(key, jobParameters.get(key));
+			}
 		}
 		builder.addJobParameters(this.jobParametersConverter.getJobParameters(properties));
 		return builder.toJobParameters();

spring-batch-core/src/test/java/org/springframework/batch/core/step/job/DefaultJobParametersExtractorTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2022 the original author or authors.
+ * Copyright 2006-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -18,10 +18,12 @@
 import org.junit.jupiter.api.Test;
 
 import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobParameter;
 import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.JobParametersBuilder;
 import org.springframework.batch.core.StepExecution;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
@@ -109,4 +111,25 @@ void testDontUseParentParameters() {
 		assertNotNull(jobParameters.getParameter("foo").getValue());
 	}
 
+	@Test
+	public void testGetKeysFromParentParametersWhenNotInExecutionContext() {
+		DefaultJobParametersExtractor extractor = new DefaultJobParametersExtractor();
+		extractor.setUseAllParentParameters(false);
+
+		JobExecution jobExecution = new JobExecution(0L,
+				new JobParametersBuilder().addString("parentParam", "val").addDouble("foo", 22.2).toJobParameters());
+
+		StepExecution stepExecution = new StepExecution("step", jobExecution);
+
+		stepExecution.getExecutionContext().put("foo", "11.1,java.lang.Double");
+		extractor.setKeys(new String[] { "foo", "parentParam" });
+
+		JobParameters jobParameters = extractor.getJobParameters(null, stepExecution);
+
+		assertThat(jobParameters.getParameter("parentParam")).isNotNull()
+			.extracting(JobParameter::getValue)
+			.isEqualTo("val");
+		assertEquals(11.1, jobParameters.getDouble("foo"));
+	}
+
 }