Remove @ConditionalOnBean(DataSource.class) from JPA config

Stacktrace is then obviously about DataSource, not EntityManager.

Fixes gh-375

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfiguration.java

@@ -19,13 +19,11 @@ package org.springframework.boot.autoconfigure.orm.jpa;
 import java.util.Map;
 
 import javax.persistence.EntityManager;
-import javax.sql.DataSource;
 
 import org.springframework.beans.factory.BeanClassLoaderAware;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionOutcome;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.SpringBootCondition;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
@@ -53,7 +51,6 @@ import org.springframework.util.ClassUtils;
 @ConditionalOnClass({ LocalContainerEntityManagerFactoryBean.class,
 		EnableTransactionManagement.class, EntityManager.class })
 @Conditional(HibernateEntityManagerCondition.class)
-@ConditionalOnBean(DataSource.class)
 @AutoConfigureAfter(DataSourceAutoConfiguration.class)
 public class HibernateJpaAutoConfiguration extends JpaBaseConfiguration implements
 		BeanClassLoaderAware {

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/AbstractJpaAutoConfigurationTests.java

@@ -23,7 +23,10 @@ import java.util.Map;
 import javax.sql.DataSource;
 
 import org.junit.After;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.springframework.beans.factory.BeanCreationException;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
 import org.springframework.boot.autoconfigure.TestAutoConfigurationPackage;
@@ -60,6 +63,9 @@ import static org.junit.Assert.assertTrue;
  */
 public abstract class AbstractJpaAutoConfigurationTests {
 
+	@Rule
+	public ExpectedException expected = ExpectedException.none();
+
 	protected AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext();
 
 	@After
@@ -69,6 +75,16 @@ public abstract class AbstractJpaAutoConfigurationTests {
 
 	protected abstract Class<?> getAutoConfigureClass();
 
+	@Test
+	public void testNoDataSource() throws Exception {
+		this.context.register(PropertyPlaceholderAutoConfiguration.class,
+				getAutoConfigureClass());
+		this.expected.expect(BeanCreationException.class);
+		this.expected.expectMessage("No qualifying bean");
+		this.expected.expectMessage("DataSource");
+		this.context.refresh();
+	}
+
 	@Test
 	public void testEntityManagerCreated() throws Exception {
 		setupTestConfiguration();