[java] more fool-proof inner class detection

java/java-psi-impl/src/com/intellij/psi/ClassFileViewProvider.java

@@ -60,23 +60,18 @@ public class ClassFileViewProvider extends SingleRootFileViewProvider {
 
   public static boolean isInnerClass(@NotNull VirtualFile file) {
     String name = file.getNameWithoutExtension();
-    int index = name.lastIndexOf('$');
-    if (index > 0 && index < name.length() - 1) {
-      String parentName = name.substring(0, index), childName = name.substring(index + 1);
-      if (file.getParent().findChild(parentName + ".class") != null) {
-        return isInnerClass(file, parentName, childName);
-      }
-    }
-    return false;
+    return name.indexOf('$') >= 0 && detectInnerClass(file);
   }
 
-  private static boolean isInnerClass(VirtualFile file, final String parentName, final String childName) {
+  private static boolean detectInnerClass(VirtualFile file) {
     Boolean isInner = IS_INNER_CLASS.get(file);
     if (isInner != null) return isInner;
 
     final Ref<Boolean> ref = Ref.create(Boolean.FALSE);
     try {
-      new ClassReader(file.contentsToByteArray(false)).accept(new ClassVisitor(Opcodes.ASM5) {
+      ClassReader reader = new ClassReader(file.contentsToByteArray(false));
+      final String className = reader.getClassName();
+      reader.accept(new ClassVisitor(Opcodes.ASM5) {
         @Override
         public void visitOuterClass(String owner, String name, String desc) {
           ref.set(Boolean.TRUE);
@@ -85,8 +80,7 @@ public class ClassFileViewProvider extends SingleRootFileViewProvider {
 
         @Override
         public void visitInnerClass(String name, String outer, String inner, int access) {
-          if ((inner == null || childName.equals(inner)) && outer != null && parentName.equals(outer.substring(outer.lastIndexOf('/') + 1)) ||
-              inner == null && outer == null && name.substring(name.lastIndexOf('/') + 1).equals(parentName + '$' + childName)) {
+          if (className.equals(name)) {
             ref.set(Boolean.TRUE);
             throw new ProcessCanceledException();
           }

java/java-tests/testData/psi/cls/mirror/src/pkg/Groovy.groovy

@@ -0,0 +1,6 @@
+package pkg
+
+class Groovy {
+  static class Inner { }
+  Runnable r = { println("I'm runnable") }
+}

java/java-tests/testData/psi/cls/mirror/src/pkg/KindaInner.java

@@ -1,3 +1,6 @@
 package pkg;
 
-class KindaInner { }
+class KindaInner {
+  static class RealInner$ { }
+  static class Real$Inner { }
+}

java/java-tests/testSrc/com/intellij/psi/ClsMirrorBuildingTest.java

@@ -166,6 +166,10 @@ public class ClsMirrorBuildingTest extends LightIdeaTestCase {
     assertTrue(isInner("pkg/Nested$Inner1$Inner2"));
     assertTrue(isInner("pkg/NormalClass$1"));
     assertTrue(isInner("pkg/LocalClass$1MyRunnable"));
+    assertTrue(isInner("pkg/KindaInner$RealInner$"));
+    assertTrue(isInner("pkg/KindaInner$Real$Inner"));
+    assertTrue(isInner("pkg/Groovy$Inner"));
+    assertTrue(isInner("pkg/Groovy$_closure1"));
     assertTrue(isInner("weird/ToStringStyle$1"));
 
     assertFalse(isInner("pkg/KindaInner$Class"));