Merge branch '2.1.x'

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/handler/NoUnboundElementsBindHandler.java

@@ -106,7 +106,23 @@ public class NoUnboundElementsBindHandler extends AbstractBindHandler {
 
 	private boolean isUnbound(ConfigurationPropertyName name,
 			ConfigurationPropertyName candidate) {
-		return name.isAncestorOf(candidate) && !this.boundNames.contains(candidate);
+		if (name.isAncestorOf(candidate)) {
+			if (!this.boundNames.contains(candidate)
+					&& !isOverriddenCollectionElement(candidate)) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	private boolean isOverriddenCollectionElement(ConfigurationPropertyName candidate) {
+		int length = candidate.getNumberOfElements();
+		if (candidate.isNumericIndex(length - 1)) {
+			ConfigurationPropertyName propertyName = candidate
+					.chop(candidate.getNumberOfElements() - 1);
+			return this.boundNames.contains(propertyName);
+		}
+		return false;
 	}
 
 }

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/bind/handler/NoUnboundElementsBindHandlerTests.java

@@ -108,6 +108,35 @@ public class NoUnboundElementsBindHandlerTests {
 		assertThat(bound.getFoo()).isEqualTo("bar");
 	}
 
+	@Test
+	public void bindWhenUsingNoUnboundElementsHandlerShouldBindIfUnboundCollectionProperties() {
+		MockConfigurationPropertySource source1 = new MockConfigurationPropertySource();
+		source1.put("example.foo[0]", "bar");
+		MockConfigurationPropertySource source2 = new MockConfigurationPropertySource();
+		source2.put("example.foo[0]", "bar");
+		source2.put("example.foo[1]", "baz");
+		this.sources.add(source1);
+		this.sources.add(source2);
+		this.binder = new Binder(this.sources);
+		NoUnboundElementsBindHandler handler = new NoUnboundElementsBindHandler();
+		ExampleWithList bound = this.binder
+				.bind("example", Bindable.of(ExampleWithList.class), handler).get();
+		assertThat(bound.getFoo()).containsExactly("bar");
+	}
+
+	@Test
+	public void bindWhenUsingNoUnboundElementsHandlerAndUnboundListElementsShouldThrowException() {
+		MockConfigurationPropertySource source = new MockConfigurationPropertySource();
+		source.put("example.foo[0]", "bar");
+		this.sources.add(source);
+		this.binder = new Binder(this.sources);
+		assertThatExceptionOfType(BindException.class)
+				.isThrownBy(() -> this.binder.bind("example", Bindable.of(Example.class),
+						new NoUnboundElementsBindHandler()))
+				.satisfies((ex) -> assertThat(ex.getCause().getMessage())
+						.contains("The elements [example.foo[0]] were left unbound"));
+	}
+
 	public static class Example {
 
 		private String foo;
@@ -122,4 +151,18 @@ public class NoUnboundElementsBindHandlerTests {
 
 	}
 
+	public static class ExampleWithList {
+
+		private List<String> foo;
+
+		public List<String> getFoo() {
+			return this.foo;
+		}
+
+		public void setFoo(List<String> foo) {
+			this.foo = foo;
+		}
+
+	}
+
 }