GH-405: Re-throw as is after recoverer

Fixes: #405

The unchecked exception is wrapped into `UndeclaredThrowableException`
if `recoverer` is in use; it is not otherwise

* Fix `RetryTemplate` to catch `UndeclaredThrowableException` from `recoveryCallback.recover()`
and re-throw its `cause` instead to re-align behavior when no recoverer provided

src/main/java/org/springframework/retry/support/RetryTemplate.java

@@ -16,6 +16,7 @@
 
 package org.springframework.retry.support;
 
+import java.lang.reflect.UndeclaredThrowableException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
@@ -545,9 +546,14 @@ public class RetryTemplate implements RetryOperations {
 		boolean doRecover = !Boolean.TRUE.equals(context.getAttribute(RetryContext.NO_RECOVERY));
 		if (recoveryCallback != null) {
 			if (doRecover) {
-				T recovered = recoveryCallback.recover(context);
-				context.setAttribute(RetryContext.RECOVERED, true);
-				return recovered;
+				try {
+					T recovered = recoveryCallback.recover(context);
+					context.setAttribute(RetryContext.RECOVERED, true);
+					return recovered;
+				}
+				catch (UndeclaredThrowableException undeclaredThrowableException) {
+					throw wrapIfNecessary(undeclaredThrowableException.getUndeclaredThrowable());
+				}
 			}
 			else {
 				logger.debug("Retry exhausted and recovery disabled for this throwable");

src/test/java/org/springframework/retry/annotation/EnableRetryTests.java

@@ -190,6 +190,9 @@ public class EnableRetryTests {
 		service.setExceptionToThrow(new IllegalArgumentException());
 		service.service();
 		assertThat(service.getCount()).isEqualTo(3);
+
+		assertThatExceptionOfType(InstantiationException.class).isThrownBy(service::reThrowAsIs).withMessage("noRetry");
+
 		context.close();
 	}
 
@@ -750,6 +753,16 @@ public class EnableRetryTests {
 			this.exceptionToThrow = exceptionToThrow;
 		}
 
+		@Retryable(noRetryFor = InstantiationException.class, recover = "noRetryRecovery")
+		public void reThrowAsIs() throws InstantiationException {
+			throw new InstantiationException("noRetry");
+		}
+
+		@Recover
+		public void noRetryRecovery(Throwable ex) throws Throwable {
+			throw ex;
+		}
+
 	}
 
 	protected static class StatefulService {