accept this refs inside anonymous classes in java 8 interfaces (IDEA-105892)

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

@@ -1378,7 +1378,7 @@ public class HighlightUtil extends HighlightUtilBase {
 
     if (expr instanceof PsiThisExpression) {
       final PsiMethod psiMethod = PsiTreeUtil.getParentOfType(expr, PsiMethod.class);
-      if (psiMethod == null || psiMethod.getContainingClass() != aClass) {
+      if (psiMethod == null || psiMethod.getContainingClass() != aClass && !isInsideDefaultMethod(psiMethod, aClass)) {
         if (aClass.isInterface()) {
           return thisNotFoundInInterfaceInfo(expr);
         }
@@ -1393,6 +1393,13 @@ public class HighlightUtil extends HighlightUtilBase {
     }
     return null;
   }
+  
+  private static boolean isInsideDefaultMethod(PsiMethod method, PsiClass aClass) {
+    while (method != null && method.getContainingClass() != aClass) {
+      method = PsiTreeUtil.getParentOfType(method, PsiMethod.class, true);
+    }
+    return method != null && method.hasModifierProperty(PsiModifier.DEFAULT);
+  }
 
   private static HighlightInfo thisNotFoundInInterfaceInfo(@NotNull PsiExpression expr) {
     return HighlightInfo.newHighlightInfo(HighlightInfoType.ERROR).range(expr).descriptionAndTooltip("Cannot find symbol variable this").create();

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/interfaceMethods/ThisAccessibility.java

@@ -0,0 +1,24 @@
+interface Bazz {
+    Bazz foo = <error descr="Cannot find symbol variable this">Bazz.this</error>;
+    static void foo1() {
+        Bazz foo = <error descr="'Bazz.this' cannot be referenced from a static context">Bazz.this</error>;
+    }
+
+    Runnable bar = new Runnable() {
+       @Override
+       public void run() {
+           Bazz f = <error descr="Cannot find symbol variable this">Bazz.this</error>;
+       }
+    };
+  
+  
+    default void foo() {
+        Bazz foo = Bazz.this;
+        Runnable r = new Runnable() {
+            @Override
+            public void run() {
+                Bazz f = Bazz.this;
+            }
+        };
+    }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/Interface8MethodsHighlightingTest.java

@@ -29,6 +29,7 @@ public class Interface8MethodsHighlightingTest extends LightDaemonAnalyzerTestCa
   public void testInheritDefaultMethodInInterface() { doTest(false, false); }
   public void testStaticMethodsInFunctionalInterface() { doTest(false, false); }
   public void testCyclicSubstitutor() { doTest(false, false); }
+  public void testThisAccessibility() { doTest(false, false); }
 
   private void doTest() {
     doTest(false, false);