java: override default: fix super qualifier for default method (IDEA-260570)

exclude class inheritance

GitOrigin-RevId: 6d731ea550391c8f62c8800d11d85728d1bd420c

java/java-impl/src/com/intellij/codeInsight/generation/OverrideImplementUtil.java

@@ -342,7 +342,7 @@ public final class OverrideImplementUtil extends OverrideImplementExploreUtil {
       for (PsiClassType type : targetClass.getSuperTypes()) {
         PsiClass superClass = type.resolve();
         if (InheritanceUtil.isInheritorOrSelf(superClass, aClass, true)) {
-          return superClass;
+          return superClass.isInterface() ? superClass : null;
         }
       }
     }

java/java-tests/testData/codeInsight/overrideImplement/afterExtensionMethods2.java

@@ -0,0 +1,14 @@
+interface A {
+  default void foo() {}
+}
+
+interface B1 extends A {}
+
+class B implements A {}
+
+class C extends B implements B1 {
+    @Override
+    public void foo() {
+        <selection><caret>super.foo();</selection>
+    }
+}

java/java-tests/testData/codeInsight/overrideImplement/beforeExtensionMethods2.java

@@ -0,0 +1,11 @@
+interface A {
+  default void foo() {}
+}
+
+interface B1 extends A {}
+
+class B implements A {}
+
+class C extends B implements B1 {
+  <caret>
+}

java/java-tests/testSrc/com/intellij/java/codeInsight/OverrideImplementTest.groovy

@@ -53,6 +53,8 @@ class OverrideImplementTest extends LightJavaCodeInsightFixtureTestCase {
   
   void testExtensionMethods1() { doTest(true) }
 
+  void testExtensionMethods2() { doTest(true) }
+
   void testSkipUnknownAnnotations() { doTest(true) }
 
   void testMultipleInheritedThrows() { doTest(false) }