change signature: don't ask about covariant overrides when types are equal, e.g. when super type is changed based on override method return type

type annotations: ensure annotations are cloned so invalidating initial type doesn't break the consequence refactoring
EA-93296 - PIEAE: PsiUtilCore.ensureValid

java/java-impl/src/com/intellij/refactoring/changeSignature/ChangeSignatureProcessor.java

@@ -193,7 +193,7 @@ public class ChangeSignatureProcessor extends ChangeSignatureProcessorBase {
             return;
           }
           final PsiType overriderType = overrider.getReturnType();
-          if (overriderType != null && type.isAssignableFrom(overriderType)) {
+          if (overriderType != null && !type.equals(overriderType) && type.isAssignableFrom(overriderType)) {
             covariantOverriderInfos.add(usageInfo);
           }
         }

java/java-psi-impl/src/com/intellij/refactoring/util/CanonicalTypes.java

@@ -58,7 +58,13 @@ public class CanonicalTypes {
     protected final TypeAnnotationProvider myProvider;
 
     public AnnotatedType(@NotNull TypeAnnotationProvider provider) {
-      myProvider = TypeAnnotationProvider.Static.create(provider.getAnnotations());
+      PsiAnnotation[] annotations = ContainerUtil.map(provider.getAnnotations(), new Function<PsiAnnotation, PsiAnnotation>() {
+        @Override
+        public PsiAnnotation fun(PsiAnnotation annotation) {
+          return (PsiAnnotation)annotation.copy();
+        }
+      }, PsiAnnotation.EMPTY_ARRAY);
+      myProvider = TypeAnnotationProvider.Static.create(annotations);
     }
   }
 

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/superMethodReturn/afterTypeAnno.java

@@ -0,0 +1,20 @@
+// "Make 'a.f' return 'java.util.List<java.lang.@N String>'" "true"
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+import java.util.List;
+
+@Target({ElementType.TYPE_USE})
+@interface N {}
+
+class a {
+ List<@N String> f() {
+   return ;
+ }
+}
+
+class b extends a {
+  List<@N String> f() {
+    return null;
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/superMethodReturn/beforeTypeAnno.java

@@ -0,0 +1,20 @@
+// "Make 'a.f' return 'java.util.List<java.lang.@N String>'" "true"
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Target;
+import java.util.List;
+
+@Target({ElementType.TYPE_USE})
+@interface N {}
+
+class a {
+ void f() {
+   return ;
+ }
+}
+
+class b extends a {
+  <caret>List<@N String> f() {
+    return null;
+  }
+}