From cb82cb180fb2f38f368712cb0fada2a577c19bc0 Mon Sep 17 00:00:00 2001
From: Dmitry Batrak <Dmitry.Batrak@jetbrains.com>
Date: Wed, 15 Feb 2017 13:14:17 +0300
Subject: [PATCH] IDEA-168069 Join Lines throws array index out of bonds on an
 empty file

---
 .../intellij/codeInsight/editorActions/JoinLinesHandler.java  | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/platform/lang-impl/src/com/intellij/codeInsight/editorActions/JoinLinesHandler.java b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/JoinLinesHandler.java
index a541b4c1e030..9c92e968866c 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/editorActions/JoinLinesHandler.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/editorActions/JoinLinesHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * 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.
@@ -142,6 +142,8 @@ public class JoinLinesHandler extends EditorActionHandler {
                                      @NotNull PsiFile psiFile,
                                      int startLine,
                                      Ref<Integer> caretRestoreOffset) {
+    if (startLine >= doc.getLineCount() - 1) return;
+
     docManager.doPostponedOperationsAndUnblockDocument(doc);
     docManager.commitDocument(doc);
     CharSequence text = doc.getCharsSequence();