child bean definition's scope attribute can be inherited from parent bean definition now (SPR-3542)

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanDefinition.java

@@ -118,9 +118,9 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 
 	private volatile Object beanClass;
 
-	private String scope = SCOPE_SINGLETON;
+	private String scope;
 
-	private boolean singleton = true;
+	private boolean singleton = false;
 
 	private boolean prototype = false;
 
@@ -281,7 +281,9 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 		if (other.getFactoryMethodName() != null) {
 			setFactoryMethodName(other.getFactoryMethodName());
 		}
-		setScope(other.getScope());
+		if (other.getScope() != null) {
+			setScope(other.getScope());
+		}
 		setAbstract(other.isAbstract());
 		setLazyInit(other.isLazyInit());
 		setRole(other.getRole());
@@ -408,7 +410,6 @@ public abstract class AbstractBeanDefinition extends BeanMetadataAttributeAccess
 	 * @see #SCOPE_PROTOTYPE
 	 */
 	public void setScope(String scope) {
-		Assert.notNull(scope, "Scope must not be null");
 		this.scope = scope;
 		this.singleton = SCOPE_SINGLETON.equals(scope);
 		this.prototype = SCOPE_PROTOTYPE.equals(scope);

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/AbstractBeanFactory.java

@@ -1113,6 +1113,11 @@ public abstract class AbstractBeanFactory extends FactoryBeanRegistrySupport imp
 					mbd.overrideFrom(bd);
 				}
 
+				// Set default singleton scope, if not configured before.
+				if (mbd.getScope() == null) {
+					mbd.setScope(RootBeanDefinition.SCOPE_SINGLETON);
+				}
+
 				// A bean contained in a non-singleton bean cannot be a singleton itself.
 				// Let's correct this on the fly here, since this might be the result of
 				// parent-child merging for the outer bean, in which case the original inner bean

org.springframework.beans/src/main/java/org/springframework/beans/factory/xml/BeanDefinitionParserDelegate.java

@@ -535,8 +535,7 @@ public class BeanDefinitionParserDelegate {
 		}
 
 		String lazyInit = ele.getAttribute(LAZY_INIT_ATTRIBUTE);
-		if (DEFAULT_VALUE.equals(lazyInit) && bd.isSingleton()) {
-			// Just apply default to singletons, as lazy-init has no meaning for prototypes.
+		if (DEFAULT_VALUE.equals(lazyInit)) {
 			lazyInit = this.defaults.getLazyInit();
 		}
 		bd.setLazyInit(TRUE_VALUE.equals(lazyInit));

org.springframework.beans/src/test/java/org/springframework/beans/factory/DefaultListableBeanFactoryTests.java

@@ -1972,7 +1972,7 @@ public final class DefaultListableBeanFactoryTests {
 	}
 
 	@Test
-	public void testImplicitScopeInheritanceForChildBeanDefinitions() throws Exception {
+	public void testScopeInheritanceForChildBeanDefinitions() throws Exception {
 		RootBeanDefinition parent = new RootBeanDefinition();
 		parent.setScope("bonanza!");
 
@@ -1984,7 +1984,7 @@ public final class DefaultListableBeanFactoryTests {
 		factory.registerBeanDefinition("child", child);
 
 		BeanDefinition def = factory.getMergedBeanDefinition("child");
-		assertTrue("Child 'scope' not overriding parent scope (it must).", def.isSingleton());
+		assertEquals("Child 'scope' not inherited", "bonanza!", def.getScope());
 	}
 
 	@Test