IDEA-341719 [java-analysis] Nullability annotation on type param doesn't apply to uses of type param

GitOrigin-RevId: 6a15d9e40e8d132e01c6a1b0b08a30ac3d33189d

java/java-impl/src/com/intellij/codeInsight/annoPackages/CheckerFrameworkSupport.java

@@ -42,8 +42,10 @@ final class CheckerFrameworkSupport implements AnnotationPackageSupport {
             // DefaultQualifier is not applicable to type parameter declarations
             if (context instanceof PsiTypeParameter) return false;
             // DefaultQualifier is not applicable to type parameter uses
-            return !(PsiUtil.getTypeByPsiElement(context) instanceof PsiClassType classType) || 
-                   !(classType.resolve() instanceof PsiTypeParameter);
+            return !(PsiUtil.getTypeByPsiElement(context) instanceof PsiClassType classType &&
+                     classType.resolve() instanceof PsiTypeParameter ||
+                     context instanceof PsiJavaCodeReferenceElement ref &&
+                     ref.resolve() instanceof PsiTypeParameter);
           });
       }
       return ContextNullabilityInfo.EMPTY;

java/java-psi-api/src/com/intellij/codeInsight/NullableNotNullManager.java

@@ -200,7 +200,7 @@ public abstract class NullableNotNullManager {
         for (PsiParameter parameter: superParameters) {
           NullabilityAnnotationInfo plain = findPlainAnnotation(parameter, false, annotations);
           // Plain not null annotation is not inherited
-          if (plain != null) return null;
+          if (plain != null && !plain.isContainer()) return null;
           NullabilityAnnotationInfo defaultInfo = findContainerAnnotation(parameter);
           if (defaultInfo != null) {
             return defaultInfo.getNullability() == Nullability.NOT_NULL ? defaultInfo.withInheritedFrom(parameter) : null;
@@ -259,6 +259,11 @@ public abstract class NullableNotNullManager {
         Nullability origNullability = holder.getNullability(annotation);
         return nullabilities.contains(origNullability) ? origNullability : null;
       }
+
+      @Override
+      public boolean isWantedNullability(@NotNull Nullability nullability) {
+        return nullabilities.contains(nullability);
+      }
     };
     NullabilityAnnotationInfo result = findPlainAnnotation(owner, false, filtered);
     return result == null || !nullabilities.contains(result.getNullability()) ? null : result;
@@ -296,7 +301,7 @@ public abstract class NullableNotNullManager {
     }
     if (type == null || type instanceof PsiPrimitiveType) return null;
     NullabilityAnnotationInfo info = type.getNullability().toNullabilityAnnotationInfo();
-    return info != null && annotations.getNullability(info.getAnnotation().getQualifiedName()) != null ? info : null;
+    return info != null && annotations.isWantedNullability(info.getNullability()) ? info : null;
   }
 
   protected @NotNull Nullability correctNullability(@NotNull Nullability nullability, @NotNull PsiAnnotation annotation) {
@@ -479,6 +484,10 @@ public abstract class NullableNotNullManager {
      * @return nullability
      */
     @Nullable Nullability getNullability(String annotation);
+    
+    default boolean isWantedNullability(@NotNull Nullability nullability) {
+      return true;
+    }
 
     /**
      * @param map from annotation qualified name to nullability

java/java-psi-api/src/com/intellij/util/JavaTypeNullabilityUtil.java

@@ -82,7 +82,12 @@ public final class JavaTypeNullabilityUtil {
     PsiElement context = classType.getPsiContext();
     return context instanceof PsiJavaCodeReferenceElement &&
            context.getParent() instanceof PsiTypeElement &&
-           context.getParent().getParent() instanceof PsiLocalVariable;
+           isLocalVariable(context.getParent().getParent());
+  }
+
+  private static boolean isLocalVariable(PsiElement element) {
+    return element instanceof PsiLocalVariable || 
+           element instanceof PsiParameter && !(element.getParent() instanceof PsiParameterList);
   }
 
   /**

java/java-tests/testData/inspection/nullableProblems/DefaultNotNullTypeParameterOverrides.java

@@ -0,0 +1,21 @@
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.NotNullByDefault;
+
+interface Test<T> {
+  @NotNull
+  T test();
+}
+@NotNullByDefault
+class TestImpl<T> implements Test<T> {
+
+  final T value;
+
+  public TestImpl(final T value) {
+    this.value = value;
+  }
+
+  @Override
+  public T test() {  
+    return this.value;
+  }
+}

java/java-tests/testSrc/com/intellij/java/codeInspection/CheckerNullityTest.java

@@ -144,7 +144,7 @@ public class CheckerNullityTest extends LightJavaCodeInsightFixtureTestCase {
       import org.checkerframework.framework.qual.*;
       
       @DefaultQualifier(NonNull.class)
-      interface Test<X> {
+      interface Test<X extends @Nullable Object> {
         String test(X x);
         X test(String x);
       }""");

java/java-tests/testSrc/com/intellij/java/codeInspection/NullableStuffInspectionTest.java

@@ -520,4 +520,8 @@ public class NullableStuffInspectionTest extends LightJavaCodeInsightFixtureTest
     addJSpecifyNullMarked(myFixture);
     doTest();
   }
+  
+  public void testDefaultNotNullTypeParameterOverrides() {
+    doTest();
+  }
 }