From 22f0f80163a6adc19c2f390b2c54a1170b5b797a Mon Sep 17 00:00:00 2001
From: Sergey Malenkov <sergey.malenkov@jetbrains.com>
Date: Thu, 21 Jul 2016 16:20:51 +0300
Subject: [PATCH] IDEA-152049 Project view collapses in unpinned mode after
 some time and changes in editor

---
 .../ide/projectView/impl/AbstractProjectViewPane.java     | 8 +++-----
 .../src/com/intellij/ide/util/treeView/TreeState.java     | 4 ++++
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPane.java b/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPane.java
index 051f42c3ebe9..67fc45cc4613 100644
--- a/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPane.java
+++ b/platform/lang-impl/src/com/intellij/ide/projectView/impl/AbstractProjectViewPane.java
@@ -438,7 +438,7 @@ public abstract class AbstractProjectViewPane implements DataProvider, Disposabl
       String subId = subPane.getAttributeValue(ATTRIBUTE_SUBID);
       TreeState treeState = new TreeState();
       treeState.readExternal(subPane);
-      myReadTreeState.put(subId, treeState);
+      if (!treeState.isEmpty()) myReadTreeState.put(subId, treeState);
     }
   }
 
@@ -458,15 +458,13 @@ public abstract class AbstractProjectViewPane implements DataProvider, Disposabl
   protected void saveExpandedPaths() {
     if (myTree != null) {
       TreeState treeState = TreeState.createOn(myTree);
-      myReadTreeState.put(getSubId(), treeState);
+      if (!treeState.isEmpty()) myReadTreeState.put(getSubId(), treeState);
     }
   }
 
   public final void restoreExpandedPaths(){
     TreeState treeState = myReadTreeState.get(getSubId());
-    if (treeState != null) {
-      treeState.applyTo(myTree);
-    }
+    if (treeState != null && !treeState.isEmpty()) treeState.applyTo(myTree);
   }
 
   public void installComparator() {
diff --git a/platform/platform-api/src/com/intellij/ide/util/treeView/TreeState.java b/platform/platform-api/src/com/intellij/ide/util/treeView/TreeState.java
index 597f0311144c..538916f6aefd 100644
--- a/platform/platform-api/src/com/intellij/ide/util/treeView/TreeState.java
+++ b/platform/platform-api/src/com/intellij/ide/util/treeView/TreeState.java
@@ -110,6 +110,10 @@ public class TreeState implements JDOMExternalizable {
     this(new ArrayList<List<PathElement>>(), new ArrayList<List<PathElement>>());
   }
 
+  public boolean isEmpty() {
+    return myExpandedPaths.isEmpty() && mySelectedPaths.isEmpty();
+  }
+
   @Override
   public void readExternal(Element element) throws InvalidDataException {
     readExternal(element, myExpandedPaths, PATH);