don't drop comment inside condition on inverting if

java/java-impl/src/com/intellij/codeInsight/intention/impl/InvertIfConditionAction.java

@@ -1,18 +1,4 @@
-/*
- * Copyright 2000-2017 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.codeInsight.intention.impl;
 
 import com.intellij.codeInsight.CodeInsightBundle;
@@ -86,16 +72,15 @@ public class InvertIfConditionAction extends PsiElementBaseIntentionAction {
 
     LOG.assertTrue(ifStatement != null);
     PsiElement block = findCodeBlock(ifStatement);
-
+    LOG.assertTrue(block != null);
     ControlFlow controlFlow = buildControlFlow(block);
-
-    PsiExpression condition = (PsiExpression) Objects.requireNonNull(ifStatement.getCondition()).copy();
-
     ifStatement = setupBranches(ifStatement, controlFlow);
+
+    PsiExpression condition = Objects.requireNonNull(ifStatement.getCondition());
     if (condition != null) {
-      PsiExpression negatedExpression =
-        JavaPsiFacade.getElementFactory(project).createExpressionFromText(BoolUtils.getNegatedExpressionText(condition), condition);
-      Objects.requireNonNull(ifStatement.getCondition()).replace(negatedExpression);
+      final CommentTracker tracker = new CommentTracker();
+      final String negatedCondition = BoolUtils.getNegatedExpressionText(condition, tracker);
+      tracker.replaceAndRestoreComments(condition, negatedCondition);
     }
 
     formatIf(ifStatement);

java/java-tests/testData/codeInsight/invertIfCondition/afterCommentInsideCondition.java

@@ -0,0 +1,12 @@
+// "Invert 'if' condition" "true"
+class A {
+    public void foo() {
+        //comment
+        if (1 != 2) {
+            System.out.println("false");
+        }
+        else {
+ System.out.println("true");
+}
+    }
+}

java/java-tests/testData/codeInsight/invertIfCondition/beforeCommentInsideCondition.java

@@ -0,0 +1,11 @@
+// "Invert 'if' condition" "true"
+class A {
+    public void foo() {
+        <caret>if (1 //comment
+                   == 2) {
+            System.out.println("true");
+        } else {
+            System.out.println("false");
+        }
+    }
+}