override clone specifics (IDEA-67754)

java/java-impl/src/com/intellij/codeInsight/daemon/impl/analysis/GenericsHighlightUtil.java

@@ -1094,6 +1094,12 @@ public class GenericsHighlightUtil {
     }
     try {
       MethodSignatureBackedByPsiMethod superMethod = SuperMethodsSearch.search(method, null, true, false).findFirst();
+      if (superMethod != null && method.getContainingClass().isInterface() && "clone".equals(superMethod.getName())) {
+        final PsiClass containingClass = superMethod.getMethod().getContainingClass();
+        if (containingClass != null && CommonClassNames.JAVA_LANG_OBJECT.equals(containingClass.getQualifiedName())) {
+          superMethod = null;
+        }
+      }
       if (superMethod == null) {
         String description = JavaErrorMessages.message("method.does.not.override.super");
         HighlightInfo highlightInfo =

java/java-impl/src/com/intellij/codeInsight/daemon/impl/analysis/HighlightMethodUtil.java

@@ -146,6 +146,14 @@ public class HighlightMethodUtil {
                                                          String detailMessage,
                                                          PsiMethod methodToHighlight) {
     if (superReturnType == null) return null;
+    if ("clone".equals(method.getName())) {
+      final PsiClass containingClass = method.getContainingClass();
+      final PsiClass superContainingClass = superMethod.getContainingClass();
+      if (containingClass != null && superContainingClass != null && containingClass.isInterface() && !superContainingClass.isInterface()) {
+        return null;
+      }
+    }
+
     PsiType substitutedSuperReturnType;
     final boolean isJdk15 = PsiUtil.isLanguageLevel5OrHigher(method);
     if (isJdk15 && !superMethodSignature.isRaw() && superMethodSignature.equals(methodSignature)) { //see 8.4.5

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/advHighlighting6/IDEADEV11877.java

@@ -1,7 +1,19 @@
 interface MyCloneable {
 
     //protected method from java.lang.Object is not implicitly declared in interface with no base interfaces
-    <error descr="'clone()' in 'MyCloneable' clashes with 'clone()' in 'java.lang.Object'; attempting to use incompatible return type">int</error> clone();
+    int clone();
 
     <error descr="'toString()' in 'MyCloneable' clashes with 'toString()' in 'java.lang.Object'; attempting to use incompatible return type">int</error> toString();
+}
+
+interface MyCloneable1 {
+  <error descr="Method does not override method from its superclass">@Override</error>
+  Object clone();
+}
+
+class MyCloneable2 {
+  @Override
+  public Object clone() {
+    return null;
+  }
 }

java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingJdk6Test.java

@@ -54,4 +54,5 @@ public class LightAdvHighlightingJdk6Test extends LightDaemonAnalyzerTestCase {
 
   public void testJavacQuirks() { setLanguageLevel(LanguageLevel.JDK_1_6); doTest(true, false); }
   public void testMethodReturnTypeSubstitutability() { setLanguageLevel(LanguageLevel.JDK_1_6); doTest(true, false); }
+  public void testIDEADEV11877() throws Exception { setLanguageLevel(LanguageLevel.JDK_1_6); doTest(false, false); }
 }

java/java-tests/testSrc/com/intellij/codeInsight/daemon/LightAdvHighlightingTest.java

@@ -185,7 +185,6 @@ public class LightAdvHighlightingTest extends LightDaemonAnalyzerTestCase {
   public void testCatchUnknownMethod() throws Exception { doTest(false, false); }
   public void testIDEADEV8822() throws Exception { doTest(false, false); }
   public void testIDEADEV9201() throws Exception { doTest(false, false); }
-  public void testIDEADEV11877() throws Exception { doTest(false, false); }
   public void testIDEADEV25784() throws Exception { doTest(false, false); }
   public void testIDEADEV13249() throws Exception { doTest(false, false); }
   public void testIDEADEV11919() throws Exception { doTest(false, false); }