PsiCorrectedClassType: do not recheck the substitutor if it's the same as delegate substitutor

May help to improve performance in IDEA-185777

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

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2016 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// Copyright 2000-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license that can be found in the LICENSE file.
 package com.intellij.psi.impl;
 
 import com.intellij.pom.java.LanguageLevel;
@@ -238,7 +224,16 @@ class TypeCorrector extends PsiTypeMapper {
 
     @Override
     public boolean isValid() {
-      return myDelegate.isValid() && myResolveResult.myMappedClass.isValid() && myResolveResult.mySubstitutor.isValid();
+      if (myDelegate.isValid() && myResolveResult.myMappedClass.isValid()) {
+        if (myDelegate instanceof PsiCorrectedClassType && ((PsiCorrectedClassType)myDelegate).myResolveResult.mySubstitutor == myResolveResult.mySubstitutor) {
+          // substitutor was already checked for delegate: no need to recheck it
+          return true;
+        }
+        if (myResolveResult.mySubstitutor.isValid()) {
+          return true;
+        }
+      }
+      return false;
     }
 
     @Override