Consistent nullability for BeanDefinitionBuilder setters

Issue: SPR-15841

spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionBuilder.java

@@ -194,7 +194,7 @@ public class BeanDefinitionBuilder {
 	 * Add an indexed constructor arg value. The current index is tracked internally
 	 * and all additions are at the present point.
 	 */
-	public BeanDefinitionBuilder addConstructorArgValue(Object value) {
+	public BeanDefinitionBuilder addConstructorArgValue(@Nullable Object value) {
 		this.beanDefinition.getConstructorArgumentValues().addIndexedArgumentValue(
 				this.constructorArgIndex++, value);
 		return this;
@@ -213,7 +213,7 @@ public class BeanDefinitionBuilder {
 	/**
 	 * Add the supplied property value under the given name.
 	 */
-	public BeanDefinitionBuilder addPropertyValue(String name, Object value) {
+	public BeanDefinitionBuilder addPropertyValue(String name, @Nullable Object value) {
 		this.beanDefinition.getPropertyValues().add(name, value);
 		return this;
 	}
@@ -231,7 +231,7 @@ public class BeanDefinitionBuilder {
 	/**
 	 * Set the init method for this definition.
 	 */
-	public BeanDefinitionBuilder setInitMethodName(String methodName) {
+	public BeanDefinitionBuilder setInitMethodName(@Nullable String methodName) {
 		this.beanDefinition.setInitMethodName(methodName);
 		return this;
 	}
@@ -239,7 +239,7 @@ public class BeanDefinitionBuilder {
 	/**
 	 * Set the destroy method for this definition.
 	 */
-	public BeanDefinitionBuilder setDestroyMethodName(String methodName) {
+	public BeanDefinitionBuilder setDestroyMethodName(@Nullable String methodName) {
 		this.beanDefinition.setDestroyMethodName(methodName);
 		return this;
 	}
@@ -250,7 +250,7 @@ public class BeanDefinitionBuilder {
 	 * @see org.springframework.beans.factory.config.BeanDefinition#SCOPE_SINGLETON
 	 * @see org.springframework.beans.factory.config.BeanDefinition#SCOPE_PROTOTYPE
 	 */
-	public BeanDefinitionBuilder setScope(String scope) {
+	public BeanDefinitionBuilder setScope(@Nullable String scope) {
 		this.beanDefinition.setScope(scope);
 		return this;
 	}

spring-beans/src/main/java/org/springframework/beans/factory/xml/AbstractSingleBeanDefinitionParser.java

@@ -79,10 +79,7 @@ public abstract class AbstractSingleBeanDefinitionParser extends AbstractBeanDef
 		BeanDefinition containingBd = parserContext.getContainingBeanDefinition();
 		if (containingBd != null) {
 			// Inner bean definition must receive same scope as containing bean.
-			String scopeName = containingBd.getScope();
-			if (scopeName != null) {
-				builder.setScope(scopeName);
-			}
+			builder.setScope(containingBd.getScope());
 		}
 		if (parserContext.isDefaultLazyInit()) {
 			// Default-lazy-init applies to custom bean definitions as well.