Revert "Nested Map should not bind to null"

This reverts commit 5406567783.

spring-boot/src/main/java/org/springframework/boot/context/properties/bind/Binder.java

@@ -298,10 +298,11 @@ public class Binder {
 		}
 		BeanPropertyBinder propertyBinder = (propertyName, propertyTarget) -> bind(
 				name.append(propertyName), propertyTarget, handler, context);
-		if (context.isProcessingName(name)) {
+		Class<?> type = target.getType().resolve();
+		if (context.hasBoundBean(type)) {
 			return null;
 		}
-		return context.withName(name, () -> {
+		return context.withBean(type, () -> {
 			Stream<?> boundBeans = BEAN_BINDERS.stream()
 					.map((b) -> b.bind(name, target, context, propertyBinder));
 			return boundBeans.filter(Objects::nonNull).findFirst().orElse(null);
@@ -352,7 +353,7 @@ public class Binder {
 		private final List<ConfigurationPropertySource> source = Arrays
 				.asList((ConfigurationPropertySource) null);
 
-		private final Deque<ConfigurationPropertyName> names = new ArrayDeque<>();
+		private final Deque<Class<?>> beans = new ArrayDeque<>();
 
 		private ConfigurationProperty configurationProperty;
 
@@ -384,13 +385,13 @@ public class Binder {
 			}
 		}
 
-		public <T> T withName(ConfigurationPropertyName name, Supplier<T> supplier) {
-			this.names.push(name);
+		public <T> T withBean(Class<?> bean, Supplier<T> supplier) {
+			this.beans.push(bean);
 			try {
 				return withIncreasedDepth(supplier);
 			}
 			finally {
-				this.names.pop();
+				this.beans.pop();
 			}
 		}
 
@@ -420,8 +421,8 @@ public class Binder {
 			return StreamSupport.stream(Binder.this.sources.spliterator(), false);
 		}
 
-		public boolean isProcessingName(ConfigurationPropertyName name) {
-			return this.names.contains(name);
+		public boolean hasBoundBean(Class<?> bean) {
+			return this.beans.contains(bean);
 		}
 
 		@Override

spring-boot/src/test/java/org/springframework/boot/context/properties/bind/BinderTests.java

@@ -19,9 +19,7 @@ package org.springframework.boot.context.properties.bind;
 import java.time.LocalDate;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.LinkedHashMap;
 import java.util.List;
-import java.util.Map;
 
 import org.assertj.core.matcher.AssertionMatcher;
 import org.junit.Before;
@@ -239,19 +237,6 @@ public class BinderTests {
 		this.binder.bind("foo", target);
 	}
 
-	@Test
-	public void nestedMapsShouldNotBindToNull() throws Exception {
-		MockConfigurationPropertySource source = new MockConfigurationPropertySource();
-		source.put("foo.value", "one");
-		source.put("foo.foos.foo1.value", "two");
-		source.put("foo.foos.foo2.value", "three");
-		this.sources.add(source);
-		BindResult<Foo> foo = this.binder.bind("foo", Foo.class);
-		assertThat(foo.get().getValue()).isNotNull();
-		assertThat(foo.get().getFoos().get("foo1").getValue()).isEqualTo("two");
-		assertThat(foo.get().getFoos().get("foo2").getValue()).isEqualTo("three");
-	}
-
 	public static class JavaBean {
 
 		private String value;
@@ -278,24 +263,4 @@ public class BinderTests {
 
 	}
 
-	static class Foo {
-
-		private String value;
-
-		private Map<String, Foo> foos = new LinkedHashMap<>();
-
-		public Map<String, Foo> getFoos() {
-			return this.foos;
-		}
-
-		public String getValue() {
-			return this.value;
-		}
-
-		public void setValue(String value) {
-			this.value = value;
-		}
-
-	}
-
 }