empty method: ensure super call is not removed if unrelated defaults are present (IDEA-202410)

java/java-analysis-impl/src/com/intellij/codeInspection/reference/RefJavaUtilImpl.java

@@ -566,11 +566,18 @@ public class RefJavaUtilImpl extends RefJavaUtil {
 
     if (hasStatements) {
       final PsiMethod[] superMethods = javaMethod.findSuperMethods();
+      int defaultCount = 0;
       for (PsiMethod superMethod : superMethods) {
         if (VisibilityUtil.compare(VisibilityUtil.getVisibilityModifier(superMethod.getModifierList()),
                                    VisibilityUtil.getVisibilityModifier(javaMethod.getModifierList())) > 0) {
           return false;
         }
+        if (superMethod.hasModifierProperty(PsiModifier.DEFAULT)) {
+          defaultCount++;
+        }
+      }
+      if (defaultCount > 1) {
+        return false;
       }
     }
     return hasStatements;

java/java-tests/testData/inspection/emptyMethod/superCall/src/Defaults.java

@@ -0,0 +1,15 @@
+
+interface Interface1 {
+  default void foo() { System.out.println("Interface1.foo()"); }
+}
+
+interface Interface2 {
+  default void foo() { System.out.println("Interface2.foo()"); }
+}
+
+interface Interface3 extends Interface1, Interface2 {
+  default void foo() {
+    Interface1.super.foo();
+    Interface2.super.foo();
+  }
+}