From 57c0d95007cee57a8f6141da48cb770f01283397 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Deleuze?= <sebastien.deleuze@broadcom.com>
Date: Fri, 3 Jan 2025 17:29:49 +0100
Subject: [PATCH] Fix detection of JSpecify annotations on parameters

See gh-28797
---
 .../springframework/core/MethodParameter.java |  3 +-
 .../core/MethodParameterTests.java            | 29 +++++++++++++++----
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/spring-core/src/main/java/org/springframework/core/MethodParameter.java b/spring-core/src/main/java/org/springframework/core/MethodParameter.java
index 068360e441..5639cf6351 100644
--- a/spring-core/src/main/java/org/springframework/core/MethodParameter.java
+++ b/spring-core/src/main/java/org/springframework/core/MethodParameter.java
@@ -412,7 +412,8 @@ public class MethodParameter {
 				return true;
 			}
 		}
-		for (AnnotatedType annotatedType : this.executable.getAnnotatedParameterTypes()) {
+		if (this.parameterIndex >= 0) {
+			AnnotatedType annotatedType = this.executable.getAnnotatedParameterTypes()[this.parameterIndex];
 			for (Annotation ann : annotatedType.getAnnotations()) {
 				if ("Nullable".equals(ann.annotationType().getSimpleName())) {
 					return true;
diff --git a/spring-core/src/test/java/org/springframework/core/MethodParameterTests.java b/spring-core/src/test/java/org/springframework/core/MethodParameterTests.java
index 715d887881..35b25c87e9 100644
--- a/spring-core/src/test/java/org/springframework/core/MethodParameterTests.java
+++ b/spring-core/src/test/java/org/springframework/core/MethodParameterTests.java
@@ -38,6 +38,7 @@ import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException
  * @author Juergen Hoeller
  * @author Sam Brannen
  * @author Phillip Webb
+ * @author Sebastien Deleuze
  */
 class MethodParameterTests {
 
@@ -51,8 +52,12 @@ class MethodParameterTests {
 
 	private MethodParameter jspecifyNullableParameter;
 
+	private MethodParameter jspecifyNonNullParameter;
+
 	private MethodParameter springNullableParameter;
 
+	private MethodParameter springNonNullParameter;
+
 
 	@BeforeEach
 	void setup() throws NoSuchMethodException {
@@ -60,10 +65,12 @@ class MethodParameterTests {
 		stringParameter = new MethodParameter(method, 0);
 		longParameter = new MethodParameter(method, 1);
 		intReturnType = new MethodParameter(method, -1);
-		Method jspecifyNullableMethod = getClass().getMethod("jspecifyNullableMethod", String.class);
+		Method jspecifyNullableMethod = getClass().getMethod("jspecifyNullableMethod", String.class, String.class);
 		jspecifyNullableParameter = new MethodParameter(jspecifyNullableMethod, 0);
-		Method springNullableMethod = getClass().getMethod("springNullableMethod", String.class);
+		jspecifyNonNullParameter = new MethodParameter(jspecifyNullableMethod, 1);
+		Method springNullableMethod = getClass().getMethod("springNullableMethod", String.class, String.class);
 		springNullableParameter = new MethodParameter(springNullableMethod, 0);
+		springNonNullParameter = new MethodParameter(springNullableMethod, 1);
 	}
 
 
@@ -250,23 +257,33 @@ class MethodParameterTests {
 		assertThat(jspecifyNullableParameter.isOptional()).isTrue();
 	}
 
+	@Test
+	void jspecifyNonNullParameter() {
+		assertThat(jspecifyNonNullParameter.isOptional()).isFalse();
+	}
+
 	@Test
 	void springNullableParameter() {
 		assertThat(springNullableParameter.isOptional()).isTrue();
 	}
 
+	@Test
+	void springNonNullParameter() {
+		assertThat(springNonNullParameter.isOptional()).isFalse();
+	}
+
 	public int method(String p1, long p2) {
 		return 42;
 	}
 
-	public @org.jspecify.annotations.Nullable String jspecifyNullableMethod(@org.jspecify.annotations.Nullable String parameter) {
-		return parameter;
+	public @org.jspecify.annotations.Nullable String jspecifyNullableMethod(@org.jspecify.annotations.Nullable String nullableParameter, String nonNullParameter) {
+		return nullableParameter;
 	}
 
 	@SuppressWarnings("deprecation")
 	@org.springframework.lang.Nullable
-	public String springNullableMethod(@org.springframework.lang.Nullable String parameter) {
-		return parameter;
+	public String springNullableMethod(@org.springframework.lang.Nullable String nullableParameter, String nonNullParameter) {
+		return nullableParameter;
 	}
 
 	@SuppressWarnings("unused")