ResponseStatusException sets detail from reason again

Closes gh-29567

spring-web/src/main/java/org/springframework/web/server/MethodNotAllowedException.java

@@ -56,8 +56,7 @@ public class MethodNotAllowedException extends ResponseStatusException {
 		}
 		this.method = method;
 		this.httpMethods = Collections.unmodifiableSet(new LinkedHashSet<>(supportedMethods));
-		getBody().setDetail(this.httpMethods.isEmpty() ?
-				getReason() : "Supported methods: " + this.httpMethods);
+		setDetail(this.httpMethods.isEmpty() ? getReason() : "Supported methods: " + this.httpMethods);
 	}
 
 

spring-web/src/main/java/org/springframework/web/server/MissingRequestValueException.java

@@ -42,7 +42,7 @@ public class MissingRequestValueException extends ServerWebInputException {
 		this.name = name;
 		this.type = type;
 		this.label = label;
-		getBody().setDetail(getReason());
+		setDetail(getReason());
 	}
 
 

spring-web/src/main/java/org/springframework/web/server/NotAcceptableStatusException.java

@@ -47,7 +47,7 @@ public class NotAcceptableStatusException extends ResponseStatusException {
 	public NotAcceptableStatusException(String reason) {
 		super(HttpStatus.NOT_ACCEPTABLE, reason, null, PARSE_ERROR_DETAIL_CODE, null);
 		this.supportedMediaTypes = Collections.emptyList();
-		getBody().setDetail("Could not parse Accept header.");
+		setDetail("Could not parse Accept header.");
 	}
 
 	/**
@@ -58,7 +58,7 @@ public class NotAcceptableStatusException extends ResponseStatusException {
 				"Could not find acceptable representation", null, null, new Object[] {mediaTypes});
 
 		this.supportedMediaTypes = Collections.unmodifiableList(mediaTypes);
-		getBody().setDetail("Acceptable representations: " + mediaTypes + ".");
+		setDetail("Acceptable representations: " + mediaTypes + ".");
 	}
 
 

spring-web/src/main/java/org/springframework/web/server/ResponseStatusException.java

@@ -23,8 +23,9 @@ import org.springframework.lang.Nullable;
 import org.springframework.web.ErrorResponseException;
 
 /**
- * Subclass of {@link ErrorResponseException} that accepts a "reason" and maps
- * it to the "detail" property of {@link org.springframework.http.ProblemDetail}.
+ * Subclass of {@link ErrorResponseException} that accepts a "reason", and by
+ * default maps that to the {@link ErrorResponseException#setDetail(String) "detail"}
+ * of the {@code ProblemDetail}.
  *
  * @author Rossen Stoyanchev
  * @author Juergen Hoeller
@@ -93,6 +94,7 @@ public class ResponseStatusException extends ErrorResponseException {
 
 		super(status, ProblemDetail.forStatus(status), cause, messageDetailCode, messageDetailArguments);
 		this.reason = reason;
+		setDetail(reason);
 	}
 
 

spring-web/src/main/java/org/springframework/web/server/UnsatisfiedRequestParameterException.java

@@ -40,7 +40,7 @@ public class UnsatisfiedRequestParameterException extends ServerWebInputExceptio
 		super(initReason(conditions, params), null, null, null, new Object[] {conditions});
 		this.conditions = conditions;
 		this.requestParams = params;
-		getBody().setDetail("Invalid request parameters.");
+		setDetail("Invalid request parameters.");
 	}
 
 	private static String initReason(List<String> conditions, MultiValueMap<String, String> queryParams) {

spring-web/src/main/java/org/springframework/web/server/UnsupportedMediaTypeStatusException.java

@@ -62,7 +62,7 @@ public class UnsupportedMediaTypeStatusException extends ResponseStatusException
 		this.supportedMediaTypes = Collections.emptyList();
 		this.bodyType = null;
 		this.method = null;
-		getBody().setDetail("Could not parse Content-Type.");
+		setDetail("Could not parse Content-Type.");
 	}
 
 	/**

spring-web/src/test/java/org/springframework/web/ErrorResponseExceptionTests.java

@@ -316,7 +316,7 @@ public class ErrorResponseExceptionTests {
 		ServerErrorException ex = new ServerErrorException("Failure", null);
 
 		assertStatus(ex, HttpStatus.INTERNAL_SERVER_ERROR);
-		assertDetail(ex, null);
+		assertDetail(ex, "Failure");
 		assertDetailMessageCode(ex, null, new Object[] {ex.getReason()});
 
 		assertThat(ex.getHeaders()).isEmpty();