Handle bind exceptions in management context

This commit updates the logic for handling binding exceptions in the
management context when it is separate from the application context.
The changes allow the exception details to be visible to
DefaultErrorAttributes without causing the servlet container to
detect an error condition.

Fixes gh-21036

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/web/servlet/CompositeHandlerExceptionResolver.java

@@ -25,6 +25,7 @@ import javax.servlet.http.HttpServletResponse;
 
 import org.springframework.beans.factory.ListableBeanFactory;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.web.servlet.error.DefaultErrorAttributes;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
 import org.springframework.web.servlet.HandlerExceptionResolver;
 import org.springframework.web.servlet.ModelAndView;
@@ -51,13 +52,8 @@ class CompositeHandlerExceptionResolver implements HandlerExceptionResolver {
 		if (this.resolvers == null) {
 			this.resolvers = extractResolvers();
 		}
-		ModelAndView resolved = this.resolvers.stream()
-				.map((resolver) -> resolver.resolveException(request, response, handler, ex)).filter(Objects::nonNull)
-				.findFirst().orElse(null);
-		if (resolved != null && resolved.isEmpty()) {
-			request.setAttribute("javax.servlet.error.exception", ex);
-		}
-		return resolved;
+		return this.resolvers.stream().map((resolver) -> resolver.resolveException(request, response, handler, ex))
+				.filter(Objects::nonNull).findFirst().orElse(null);
 	}
 
 	private List<HandlerExceptionResolver> extractResolvers() {
@@ -66,6 +62,7 @@ class CompositeHandlerExceptionResolver implements HandlerExceptionResolver {
 		list.remove(this);
 		AnnotationAwareOrderComparator.sort(list);
 		if (list.isEmpty()) {
+			list.add(new DefaultErrorAttributes());
 			list.add(new DefaultHandlerExceptionResolver());
 		}
 		return list;

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/web/servlet/CompositeHandlerExceptionResolverTests.java

@@ -67,7 +67,6 @@ class CompositeHandlerExceptionResolverTests {
 		ModelAndView resolved = resolver.resolveException(this.request, this.response, null, exception);
 		assertThat(resolved).isNotNull();
 		assertThat(resolved.isEmpty()).isTrue();
-		assertThat(this.request.getAttribute("javax.servlet.error.exception")).isSameAs(exception);
 	}
 
 	private void load(Class<?>... configs) {