From 0d71a383ce67983ebb131655a6ab4cbb7a710ae3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yann=20C=C3=A9bron?= <yann.cebron@jetbrains.com>
Date: Mon, 18 May 2015 18:33:56 +0200
Subject: [PATCH] FinderRecursivePanel#mergeListItems: optimize when adding
 items to empty list (initial population)

---
 .../src/com/intellij/ui/FinderRecursivePanel.java   | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/platform/platform-impl/src/com/intellij/ui/FinderRecursivePanel.java b/platform/platform-impl/src/com/intellij/ui/FinderRecursivePanel.java
index 6014cb829993..c3943d0f31d3 100644
--- a/platform/platform-impl/src/com/intellij/ui/FinderRecursivePanel.java
+++ b/platform/platform-impl/src/com/intellij/ui/FinderRecursivePanel.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2014 JetBrains s.r.o.
+ * Copyright 2000-2015 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.
@@ -533,7 +533,13 @@ public abstract class FinderRecursivePanel<T> extends JBSplitter implements Data
     });
   }
 
-  public static <T> void mergeListItems(@NotNull CollectionListModel<T> listModel, @NotNull List<T> newItems) {
+  static <T> void mergeListItems(@NotNull CollectionListModel<T> listModel, @NotNull List<T> newItems) {
+    boolean isEmptyList = listModel.getSize() == 0;
+    if (isEmptyList) {
+      listModel.add(newItems);
+      return;
+    }
+
     // remove items
     for (int i = listModel.getSize() - 1; i >= 0; i--) {
       if (!newItems.contains(listModel.getElementAt(i))) {
@@ -574,7 +580,8 @@ public abstract class FinderRecursivePanel<T> extends JBSplitter implements Data
         final FinderRecursivePanel childPanel = (FinderRecursivePanel)myChild;
         if (withUpdatePanel) {
           childPanel.init();
-        } else {
+        }
+        else {
           childPanel.initWithoutUpdatePanel();
         }
       }