From 4060d284923e2e802af8408b60f39b9fc1885114 Mon Sep 17 00:00:00 2001
From: Alexey Kudravtsev <cdr@intellij.com>
Date: Mon, 3 Dec 2018 13:11:48 +0300
Subject: [PATCH] followup for IDEA-CR-40159

---
 .../openapi/vfs/impl/VirtualFilePointerContainerImpl.java     | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/platform/core-impl/src/com/intellij/openapi/vfs/impl/VirtualFilePointerContainerImpl.java b/platform/core-impl/src/com/intellij/openapi/vfs/impl/VirtualFilePointerContainerImpl.java
index 5702cf351133..d972b22044df 100644
--- a/platform/core-impl/src/com/intellij/openapi/vfs/impl/VirtualFilePointerContainerImpl.java
+++ b/platform/core-impl/src/com/intellij/openapi/vfs/impl/VirtualFilePointerContainerImpl.java
@@ -405,8 +405,8 @@ public class VirtualFilePointerContainerImpl extends TraceableDisposable impleme
       if (!jars.contains(pointer)) toAddJars.add(pointer);
       if (!list.contains(pointer)) toAddList.add(pointer);
     });
-    (recursively ? myJarRecursiveDirectories : myJarDirectories).addAll(toAddJars);
-    myList.addAll(toAddList); // hack. jar directories need to be contained in class roots too (for externalization compatibility) but be ignored in getFiles()
+    (recursively ? myJarRecursiveDirectories : myJarDirectories).addAllAbsent(toAddJars);
+    myList.addAllAbsent(toAddList); // hack. jar directories need to be contained in class roots too (for externalization compatibility) but be ignored in getFiles()
     dropCaches();
   }