preserve comments: merge call seq to chain

plugins/IntentionPowerPak/src/com/siyeh/ipp/concatenation/MergeCallSequenceToChainIntention.java

@@ -19,6 +19,7 @@ import com.intellij.psi.*;
 import com.intellij.psi.util.PsiTreeUtil;
 import com.intellij.psi.util.PsiUtil;
 import com.siyeh.ig.PsiReplacementUtil;
+import com.siyeh.ig.psiutils.CommentTracker;
 import com.siyeh.ig.psiutils.ParenthesesUtils;
 import com.siyeh.ipp.base.Intention;
 import com.siyeh.ipp.base.PsiElementPredicate;
@@ -52,8 +53,10 @@ public class MergeCallSequenceToChainIntention extends Intention {
       return;
     }
     PsiMethodCallExpression methodCallExpression = getRootMethodCallExpression((PsiMethodCallExpression)expression1);
+    CommentTracker tracker = new CommentTracker();
     while (true) {
       final PsiExpressionList argumentList = methodCallExpression.getArgumentList();
+      tracker.markUnchanged(argumentList);
       final PsiReferenceExpression methodExpression = methodCallExpression.getMethodExpression();
       final String methodName = methodExpression.getReferenceName();
       newMethodCallExpression.append('.').append(methodName).append(argumentList.getText());
@@ -64,8 +67,8 @@ public class MergeCallSequenceToChainIntention extends Intention {
       }
       methodCallExpression = (PsiMethodCallExpression)grandParent;
     }
-    PsiReplacementUtil.replaceExpression(expression, newMethodCallExpression.toString());
-    nextSibling.delete();
+    PsiReplacementUtil.replaceExpression(expression, newMethodCallExpression.toString(), false);
+    tracker.deleteAndRestoreComments(nextSibling);
   }
 
   private static PsiMethodCallExpression getRootMethodCallExpression(PsiMethodCallExpression expression) {

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/merge_sequence/Comments.java

@@ -0,0 +1,10 @@
+// Copyright 2000-2017 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.siyeh.ipp.concatenation.merge_sequence;
+
+class Append {
+
+  void foo(StringBuilder s) {
+    s.append(1)/*in source*/.app<caret>end(2);
+    s.append(3)/*before dot*/./*after dot*/append(4/*in arg*/);//after end
+  }
+}

plugins/IntentionPowerPak/test/com/siyeh/ipp/concatenation/merge_sequence/Comments_after.java

@@ -0,0 +1,12 @@
+// Copyright 2000-2017 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.siyeh.ipp.concatenation.merge_sequence;
+
+class Append {
+
+  void foo(StringBuilder s) {
+      s.append(1)/*in source*/.append(2).append(3).append(4/*in arg*/);
+      /*before dot*/
+      /*after dot*/
+      //after end
+  }
+}

plugins/IntentionPowerPak/testSrc/com/siyeh/ipp/concatenation/MergeCallSequenceToChainIntentionTest.java

@@ -27,6 +27,7 @@ public class MergeCallSequenceToChainIntentionTest extends IPPTestCase {
   public void testAppend() { doTest(); }
   public void testParentheses() { doTest(); }
   public void testParentheses2() { doTest(); }
+  public void testComments() { doTest(); }
 
   @Override
   protected String getIntentionName() {