diff --git a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/project/manage/SourceFolderManagerImpl.kt b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/project/manage/SourceFolderManagerImpl.kt
index 68e2f11e4617..e01cc6215729 100644
--- a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/project/manage/SourceFolderManagerImpl.kt
+++ b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/service/project/manage/SourceFolderManagerImpl.kt
@@ -3,11 +3,14 @@ package com.intellij.openapi.externalSystem.service.project.manage
 
 import com.intellij.ide.projectView.actions.MarkRootActionBase
 import com.intellij.openapi.Disposable
+import com.intellij.openapi.application.TransactionGuard
 import com.intellij.openapi.externalSystem.util.DisposeAwareProjectChange
 import com.intellij.openapi.externalSystem.util.ExternalSystemApiUtil
+import com.intellij.openapi.externalSystem.util.PathPrefixTreeMapImpl
 import com.intellij.openapi.module.Module
 import com.intellij.openapi.project.Project
 import com.intellij.openapi.roots.ModuleRootManager
+import com.intellij.openapi.util.Computable
 import com.intellij.openapi.util.Disposer
 import com.intellij.openapi.util.io.FileUtil
 import com.intellij.openapi.vfs.*
@@ -20,13 +23,12 @@ class SourceFolderManagerImpl(private val project: Project) : SourceFolderManage
   private var isDisposed = false
   private val mutex = Any()
   private val postponedSourceFolderCreator = PostponedSourceFolderCreator()
-  private val sourceFolders = THashMap<String, SourceFolderModel>(FileUtil.PATH_HASHING_STRATEGY)
+  private val sourceFolders = PathPrefixTreeMapImpl<SourceFolderModel>()
   private val sourceFoldersByModule = THashMap<String, ModuleModel>()
 
   override fun addSourceFolder(module: Module, url: String, type: JpsModuleSourceRootType<*>) {
-    val sourceFolder = SourceFolderModel(module, type, "")
     synchronized(mutex) {
-      sourceFolders[url] = sourceFolder
+      sourceFolders[url] = SourceFolderModel(module, url, type, "")
       val moduleModel = sourceFoldersByModule.getOrPut(module.name) {
         ModuleModel(module).also {
           Disposer.register(module, it)
@@ -34,6 +36,10 @@ class SourceFolderManagerImpl(private val project: Project) : SourceFolderManage
       }
       moduleModel.sourceFolders.add(url)
     }
+    TransactionGuard.getInstance().submitTransactionLater(this, Runnable {
+      val virtualFileManager = VirtualFileManager.getInstance()
+      virtualFileManager.refreshAndFindFileByUrl(url)
+    })
   }
 
   override fun setSourceFolderPackagePrefix(url: String, packagePrefix: String) {
@@ -57,42 +63,60 @@ class SourceFolderManagerImpl(private val project: Project) : SourceFolderManage
     virtualFileManager.removeVirtualFileListener(postponedSourceFolderCreator)
   }
 
-  private fun remove(url: String): SourceFolderModel? {
-    return synchronized(mutex) {
-      sourceFolders.remove(url)
-    }
-  }
-
   fun isDisposed() = isDisposed
 
   fun getSourceFolders(moduleName: String) = synchronized(mutex) {
     sourceFoldersByModule[moduleName]?.sourceFolders
   }
 
+  private fun unsafeRemoveSourceFolder(url: String) {
+    val sourceFolder = sourceFolders.remove(url) ?: return
+    val module = sourceFolder.module
+    val moduleModel = sourceFoldersByModule[module.name] ?: return
+    val sourceFolders = moduleModel.sourceFolders
+    sourceFolders.remove(url)
+    if (sourceFolders.isEmpty()) {
+      sourceFoldersByModule.remove(module.name)
+    }
+  }
+
   private inner class PostponedSourceFolderCreator : VirtualFileListener {
     override fun fileCreated(event: VirtualFileEvent) {
+      val sourceFoldersToChange = ArrayList<SourceFolderModel>()
+      val virtualFileManager = VirtualFileManager.getInstance()
+      synchronized(mutex) {
+        for (sourceFolder in sourceFolders.getAllDescendants(event.file.url)) {
+          val sourceFolderFile = ExternalSystemApiUtil.doWriteAction(Computable<VirtualFile> {
+            virtualFileManager.refreshAndFindFileByUrl(sourceFolder.url)
+          })
+          if (sourceFolderFile != null && sourceFolderFile.isValid) {
+            sourceFoldersToChange.add(sourceFolder)
+            unsafeRemoveSourceFolder(sourceFolder.url)
+          }
+        }
+      }
       ExternalSystemApiUtil.executeProjectChangeAction(false, object : DisposeAwareProjectChange(project) {
         override fun execute() {
-          val sourceFolderUrl = event.file.url
-          val (module, type, packagePrefix) = remove(sourceFolderUrl) ?: return
-          val moduleManager = ModuleRootManager.getInstance(module)
-          val modifiableModuleModel = moduleManager.modifiableModel
-          try {
-            val contentEntry = MarkRootActionBase.findContentEntry(modifiableModuleModel, event.file)
-            if (contentEntry != null) {
-              val sourceFolder = contentEntry.addSourceFolder(sourceFolderUrl, type)
-              sourceFolder.packagePrefix = packagePrefix
+          for ((module, url, type, packagePrefix) in sourceFoldersToChange) {
+            val moduleManager = ModuleRootManager.getInstance(module)
+            val modifiableModuleModel = moduleManager.modifiableModel
+            try {
+              val contentEntry = MarkRootActionBase.findContentEntry(modifiableModuleModel, event.file)
+              if (contentEntry != null) {
+                val sourceFolder = contentEntry.addSourceFolder(url, type)
+                sourceFolder.packagePrefix = packagePrefix
+              }
+            }
+            finally {
+              modifiableModuleModel.commit()
             }
-          }
-          finally {
-            modifiableModuleModel.commit()
           }
         }
       })
     }
   }
 
-  private data class SourceFolderModel(val module: Module, val type: JpsModuleSourceRootType<*>, var packagePrefix: String)
+  private data class SourceFolderModel(val module: Module, val url: String, val type: JpsModuleSourceRootType<*>, var packagePrefix: String)
 
   private inner class ModuleModel(val module: Module, val sourceFolders: MutableSet<String>) : Disposable {
     constructor(module: Module) : this(module, THashSet(FileUtil.PATH_HASHING_STRATEGY))
diff --git a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PathPrefixTreeMap.kt b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PathPrefixTreeMap.kt
new file mode 100644
index 000000000000..d33f2ee3bdda
--- /dev/null
+++ b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PathPrefixTreeMap.kt
@@ -0,0 +1,34 @@
+// Copyright 2000-2018 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.intellij.openapi.externalSystem.util
+
+/**
+ * [PrefixTreeMap] uses keys, that is specified by the file system paths.
+ * @see PrefixTreeMap
+ */
+interface PathPrefixTreeMap<V> : PrefixTreeMap<String, V> {
+
+  /**
+   * @see PrefixTreeMap.get
+   */
+  operator fun get(path: String): V?
+
+  /**
+   * @see PrefixTreeMap.set
+   */
+  operator fun set(path: String, value: V): V?
+
+  /**
+   * @see PrefixTreeMap.remove
+   */
+  fun remove(path: String): V?
+
+  /**
+   * @see PrefixTreeMap.contains
+   */
+  fun contains(path: String): Boolean
+
+  /**
+   * @see PrefixTreeMap.getAllDescendants
+   */
+  fun getAllDescendants(path: String): List<V>
+}
\ No newline at end of file
diff --git a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PathPrefixTreeMapImpl.kt b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PathPrefixTreeMapImpl.kt
new file mode 100644
index 000000000000..3745a9b5e30d
--- /dev/null
+++ b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PathPrefixTreeMapImpl.kt
@@ -0,0 +1,25 @@
+// Copyright 2000-2018 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.intellij.openapi.externalSystem.util
+
+import com.intellij.openapi.util.io.FileUtil
+
+class PathPrefixTreeMapImpl<V>(
+  private val pathSeparator: String = "/",
+  private val removeLastSlash: Boolean = true
+) : PathPrefixTreeMap<V>, PrefixTreeMapImpl<String, V>(FileUtil.PATH_HASHING_STRATEGY) {
+
+  override operator fun get(path: String): V? = get(path.toPrefixList())
+
+  override operator fun set(path: String, value: V): V? = set(path.toPrefixList(), value)
+
+  override fun remove(path: String): V? = remove(path.toPrefixList())
+
+  override fun contains(path: String): Boolean = contains(path.toPrefixList())
+
+  override fun getAllDescendants(path: String): List<V> = getAllDescendants(path.toPrefixList())
+
+  private fun String.toPrefixList(): List<String> {
+    val path = if (removeLastSlash) removeSuffix(pathSeparator) else this
+    return path.split(pathSeparator)
+  }
+}
\ No newline at end of file
diff --git a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PrefixTreeMap.kt b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PrefixTreeMap.kt
new file mode 100644
index 000000000000..a624fa9999c5
--- /dev/null
+++ b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PrefixTreeMap.kt
@@ -0,0 +1,49 @@
+// Copyright 2000-2018 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.intellij.openapi.externalSystem.util
+
+/**
+ * Map for fast finding values by the prefix of them keys
+ */
+interface PrefixTreeMap<K, V> {
+
+  /**
+   * Gets value from the storage by the specified [path]
+   *
+   * @param path is key identificator
+   * @return stored value with the specified [path], null if [path] not found
+   */
+  operator fun get(path: List<K>): V?
+
+  /**
+   * Sets value in the storage by the specified [path]
+   *
+   * @param path is key identificator
+   * @param value is value to store
+   * @return previous stored value with the specified [path], null if previous [path] not found
+   */
+  operator fun set(path: List<K>, value: V): V?
+
+  /**
+   * Removes value from the storage by the specified [path]
+   *
+   * @param path is key identificator
+   * @return stored value with the specified [path], null if stored [path] not found
+   */
+  fun remove(path: List<K>): V?
+
+  /**
+   * Checks existence of [path] in the storage
+   *
+   * @param path is key identificator
+   * @return result of existence checking
+   */
+  fun contains(path: List<K>): Boolean
+
+  /**
+   * Gets all values with a key, for which [path] is an ancestor
+   *
+   * @param path is key identificator
+   * @return list of stored values, [emptyList] if [path] not found
+   */
+  fun getAllDescendants(path: List<K>): List<V>
+}
\ No newline at end of file
diff --git a/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PrefixTreeMapImpl.kt b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PrefixTreeMapImpl.kt
new file mode 100644
index 000000000000..3ebc6e522bce
--- /dev/null
+++ b/platform/external-system-impl/src/com/intellij/openapi/externalSystem/util/PrefixTreeMapImpl.kt
@@ -0,0 +1,93 @@
+// Copyright 2000-2018 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.intellij.openapi.externalSystem.util
+
+import com.intellij.util.containers.FList
+import gnu.trove.THashMap
+import gnu.trove.TObjectHashingStrategy
+
+open class PrefixTreeMapImpl<K, V>(private val strategy: TObjectHashingStrategy<K>? = null) : PrefixTreeMap<K, V> {
+
+  private val root = Node()
+
+  override operator fun get(path: List<K>) = root.get(path.toFList())?.getValue()
+
+  override operator fun set(path: List<K>, value: V) = root.put(path.toFList(), value)
+
+  override fun remove(path: List<K>) = root.remove(path.toFList())
+
+  override fun contains(path: List<K>) = root.contains(path.toFList())
+
+  override fun getAllDescendants(path: List<K>) = root.get(path.toFList())?.getAllDescendants() ?: emptyList()
+
+  private inner class Node {
+    private val children = strategy?.let { THashMap<K, Node>(it) } ?: THashMap()
+    private val isLeaf get() = children.isEmpty
+    private val isInvalid get() = isLeaf && !isPresent
+    private var isPresent: Boolean = false
+    private var value: V? = null
+
+    fun getValue() = value
+
+    fun put(path: FList<K>, value: V): V? {
+      val (head, tail) = path
+      val child = children.getOrPut(head) { Node() }
+      if (tail.isEmpty()) {
+        val previousValue = child.value
+        child.value = value
+        child.isPresent = true
+        return previousValue
+      }
+      else return child.put(tail, value)
+    }
+
+    fun remove(path: FList<K>): V? {
+      val (head, tail) = path
+      val child = children[head] ?: return null
+      if (tail.isEmpty()) {
+        val value = child.value
+        child.value = null
+        child.isPresent = false
+        return value
+      }
+      else {
+        val result = child.remove(tail)
+        if (child.isInvalid) {
+          children.remove(head)
+        }
+        return result
+      }
+    }
+
+    fun contains(path: FList<K>): Boolean {
+      val (head, tail) = path
+      val child = children[head] ?: return false
+      return when {
+        tail.isEmpty() -> child.isPresent
+        else -> child.contains(tail)
+      }
+    }
+
+    fun get(path: FList<K>): Node? {
+      val (head, tail) = path
+      val child = children[head] ?: return null
+      return when {
+        tail.isEmpty() -> child
+        else -> child.get(tail)
+      }
+    }
+
+    fun getAllDescendants(): List<V> {
+      val result = children.flatMap { it.value.getAllDescendants() }.toMutableList()
+      value?.let { result.add(it) }
+      return result
+    }
+  }
+
+  companion object {
+    private operator fun <E> FList<E>.component1() = head
+
+    private operator fun <E> FList<E>.component2() = tail
+
+    private fun <E> List<E>.toFList() = FList.createFromReversed(asReversed())
+  }
+}
\ No newline at end of file
diff --git a/platform/external-system-impl/testSrc/com/intellij/openapi/externalSystem/service/project/manage/PathPrefixTreeMapImplTest.kt b/platform/external-system-impl/testSrc/com/intellij/openapi/externalSystem/service/project/manage/PathPrefixTreeMapImplTest.kt
new file mode 100644
index 000000000000..7fdea6a05d3f
--- /dev/null
+++ b/platform/external-system-impl/testSrc/com/intellij/openapi/externalSystem/service/project/manage/PathPrefixTreeMapImplTest.kt
@@ -0,0 +1,241 @@
+// Copyright 2000-2018 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.intellij.openapi.externalSystem.service.project.manage
+
+import com.intellij.openapi.externalSystem.util.PathPrefixTreeMapImpl
+import com.intellij.testFramework.UsefulTestCase
+import org.junit.Test
+
+class PathPrefixTreeMapImplTest : UsefulTestCase() {
+
+  @Test
+  fun `test map filling`() {
+    val map = PathPrefixTreeMapImpl<Int>()
+    map["C://path/to/my/dir3"] = 30
+    map["C://path/to/my/dir4"] = 10
+    map["C://path/to/dir1"] = 11
+    map["C://path/to/dir2"] = 21
+    map["C://path/to/my"] = 43
+    map["C://path"] = 13
+    assertEquals(map["C://path/to/my/dir1"], null)
+    assertEquals(map["C://path/to/my/dir2"], null)
+    assertEquals(map["C://path/to/my/dir3"], 30)
+    assertEquals(map["C://path/to/my/dir4"], 10)
+    assertEquals(map["C://path/to/dir1"], 11)
+    assertEquals(map["C://path/to/dir2"], 21)
+    assertEquals(map["C://path/to/dir3"], null)
+    assertEquals(map["C://path/to/dir4"], null)
+    assertEquals(map["C://path/to/my"], 43)
+    assertEquals(map["C://path"], 13)
+    assertFalse(map.contains("C://path/to/my/dir1"))
+    assertFalse(map.contains("C://path/to/my/dir2"))
+    assertTrue(map.contains("C://path/to/my/dir3"))
+    assertTrue(map.contains("C://path/to/my/dir4"))
+    assertTrue(map.contains("C://path/to/dir1"))
+    assertTrue(map.contains("C://path/to/dir2"))
+    assertFalse(map.contains("C://path/to/dir3"))
+    assertFalse(map.contains("C://path/to/dir4"))
+    assertTrue(map.contains("C://path/to/my"))
+    assertTrue(map.contains("C://path"))
+    map["C://path/to/my/dir1"] = 10
+    map["C://path/to/my/dir2"] = 20
+    map["C://path/to/dir3"] = 30
+    map["C://path/to/dir4"] = 11
+    assertEquals(map["C://path/to/my/dir1"], 10)
+    assertEquals(map["C://path/to/my/dir2"], 20)
+    assertEquals(map["C://path/to/my/dir3"], 30)
+    assertEquals(map["C://path/to/my/dir4"], 10)
+    assertEquals(map["C://path/to/dir1"], 11)
+    assertEquals(map["C://path/to/dir2"], 21)
+    assertEquals(map["C://path/to/dir3"], 30)
+    assertEquals(map["C://path/to/dir4"], 11)
+    assertEquals(map["C://path/to/my"], 43)
+    assertEquals(map["C://path"], 13)
+    assertTrue(map.contains("C://path/to/my/dir1"))
+    assertTrue(map.contains("C://path/to/my/dir2"))
+    assertTrue(map.contains("C://path/to/my/dir3"))
+    assertTrue(map.contains("C://path/to/my/dir4"))
+    assertTrue(map.contains("C://path/to/dir1"))
+    assertTrue(map.contains("C://path/to/dir2"))
+    assertTrue(map.contains("C://path/to/dir3"))
+    assertTrue(map.contains("C://path/to/dir4"))
+    assertTrue(map.contains("C://path/to/my"))
+    assertTrue(map.contains("C://path"))
+  }
+
+  @Test
+  fun `test map removes`() {
+    val map = PathPrefixTreeMapImpl<Int>()
+    map["C://path/to/my/dir1"] = 10
+    map["C://path/to/my/dir2"] = 20
+    map["C://path/to/my/dir3"] = 30
+    map["C://path/to/my/dir4"] = 10
+    map["C://path/to/dir1"] = 11
+    map["C://path/to/dir2"] = 21
+    map["C://path/to/dir3"] = 30
+    map["C://path/to/dir4/"] = 11
+    map["C://path/to/my"] = 43
+    map["C://path"] = 13
+    assertEquals(map["C://path/to/my/dir1"], 10)
+    assertEquals(map["C://path/to/my/dir2"], 20)
+    assertEquals(map["C://path/to/my/dir3"], 30)
+    assertEquals(map["C://path/to/my/dir4"], 10)
+    assertEquals(map["C://path/to/dir1"], 11)
+    assertEquals(map["C://path/to/dir2"], 21)
+    assertEquals(map["C://path/to/dir3"], 30)
+    assertEquals(map["C://path/to/dir4"], 11)
+    assertEquals(map["C://path/to/my"], 43)
+    assertEquals(map["C://path"], 13)
+    assertTrue(map.contains("C://path/to/my/dir1"))
+    assertTrue(map.contains("C://path/to/my/dir2"))
+    assertTrue(map.contains("C://path/to/my/dir3"))
+    assertTrue(map.contains("C://path/to/my/dir4"))
+    assertTrue(map.contains("C://path/to/dir1"))
+    assertTrue(map.contains("C://path/to/dir2"))
+    assertTrue(map.contains("C://path/to/dir3"))
+    assertTrue(map.contains("C://path/to/dir4"))
+    assertTrue(map.contains("C://path/to/my"))
+    assertTrue(map.contains("C://path"))
+    map.remove("C://path/to/my/dir1/")
+    map.remove("C://path/to/my/dir2")
+    map.remove("C://path/to/dir3")
+    map.remove("C://path/to/dir4")
+    assertEquals(map["C://path/to/my/dir1"], null)
+    assertEquals(map["C://path/to/my/dir2"], null)
+    assertEquals(map["C://path/to/my/dir3"], 30)
+    assertEquals(map["C://path/to/my/dir4"], 10)
+    assertEquals(map["C://path/to/dir1"], 11)
+    assertEquals(map["C://path/to/dir2"], 21)
+    assertEquals(map["C://path/to/dir3/"], null)
+    assertEquals(map["C://path/to/dir4"], null)
+    assertEquals(map["C://path/to/my"], 43)
+    assertEquals(map["C://path"], 13)
+    assertFalse(map.contains("C://path/to/my/dir1"))
+    assertFalse(map.contains("C://path/to/my/dir2"))
+    assertTrue(map.contains("C://path/to/my/dir3"))
+    assertTrue(map.contains("C://path/to/my/dir4"))
+    assertTrue(map.contains("C://path/to/dir1"))
+    assertTrue(map.contains("C://path/to/dir2"))
+    assertFalse(map.contains("C://path/to/dir3"))
+    assertFalse(map.contains("C://path/to/dir4"))
+    assertTrue(map.contains("C://path/to/my"))
+    assertTrue(map.contains("C://path"))
+  }
+
+
+  @Test
+  fun `test containing nullable values`() {
+    val map = PathPrefixTreeMapImpl<Int?>()
+    map["C://path/to/my/dir1"] = null
+    map["C://path/to/my/dir2"] = 20
+    map["C://path/to/my/dir3/"] = null
+    map["C://path/to/my/dir4/"] = 10
+    map["C://path/to/dir1"] = null
+    map["C://path/to/dir2"] = 21
+    map["C://path/to/dir3"] = null
+    map["C://path/to/dir4"] = 11
+    map["C://path/to/my"] = 43
+    map["C://path"] = 13
+    assertEquals(map["C://path/to/my/dir1"], null)
+    assertEquals(map["C://path/to/my/dir2"], 20)
+    assertEquals(map["C://path/to/my/dir3"], null)
+    assertEquals(map["C://path/to/my/dir4"], 10)
+    assertEquals(map["C://path/to/dir1"], null)
+    assertEquals(map["C://path/to/dir2"], 21)
+    assertEquals(map["C://path/to/dir3"], null)
+    assertEquals(map["C://path/to/dir4/"], 11)
+    assertEquals(map["C://path/to/my"], 43)
+    assertEquals(map["C://path"], 13)
+    assertTrue(map.contains("C://path/to/my/dir1"))
+    assertTrue(map.contains("C://path/to/my/dir2"))
+    assertTrue(map.contains("C://path/to/my/dir3"))
+    assertTrue(map.contains("C://path/to/my/dir4/"))
+    assertTrue(map.contains("C://path/to/dir1"))
+    assertTrue(map.contains("C://path/to/dir2"))
+    assertTrue(map.contains("C://path/to/dir3"))
+    assertTrue(map.contains("C://path/to/dir4"))
+    assertTrue(map.contains("C://path/to/my"))
+    assertTrue(map.contains("C://path"))
+    map.remove("C://path/to/my/dir1")
+    map.remove("C://path/to/my/dir2")
+    map.remove("C://path/to/dir3")
+    map.remove("C://path/to/dir4")
+    assertEquals(map["C://path/to/my/dir1"], null)
+    assertEquals(map["C://path/to/my/dir2"], null)
+    assertEquals(map["C://path/to/my/dir3"], null)
+    assertEquals(map["C://path/to/my/dir4"], 10)
+    assertEquals(map["C://path/to/dir1/"], null)
+    assertEquals(map["C://path/to/dir2"], 21)
+    assertEquals(map["C://path/to/dir3"], null)
+    assertEquals(map["C://path/to/dir4"], null)
+    assertEquals(map["C://path/to/my"], 43)
+    assertEquals(map["C://path"], 13)
+    assertFalse(map.contains("C://path/to/my/dir1/"))
+    assertFalse(map.contains("C://path/to/my/dir2"))
+    assertTrue(map.contains("C://path/to/my/dir3"))
+    assertTrue(map.contains("C://path/to/my/dir4"))
+    assertTrue(map.contains("C://path/to/dir1"))
+    assertTrue(map.contains("C://path/to/dir2"))
+    assertFalse(map.contains("C://path/to/dir3"))
+    assertFalse(map.contains("C://path/to/dir4"))
+    assertTrue(map.contains("C://path/to/my"))
+    assertTrue(map.contains("C://path"))
+  }
+
+  @Test
+  fun `test get all elements under dir`() {
+    val map = PathPrefixTreeMapImpl<Int?>()
+    map["C://path/to/my/dir1/"] = 10
+    map["C://path/to/my/dir2"] = 20
+    map["C://path/to/my/dir3/"] = 30
+    map["C://path/to/my/dir4"] = 10
+    map["C://path/to/dir1"] = 11
+    map["C://path/to/dir2/"] = 21
+    map["C://path/to/dir3"] = 30
+    map["C://path/to/dir4/"] = 11
+    map["C://path/to/my"] = 43
+    map["C://path"] = 13
+    val underMy = map.getAllDescendants("C://path/to/my").toSet()
+    assertEquals(setOf(10, 20, 30, 10, 43), underMy)
+    val underMyDir = map.getAllDescendants("C://path/to/my/").toSet()
+    assertEquals(setOf(10, 20, 30, 10, 43), underMyDir)
+    val underTo = map.getAllDescendants("C://path/to").toSet()
+    assertEquals(setOf(10, 20, 30, 10, 43, 11, 21, 30, 11, 43), underTo)
+    val underToDir = map.getAllDescendants("C://path/to/").toSet()
+    assertEquals(setOf(10, 20, 30, 10, 43, 11, 21, 30, 11, 43), underToDir)
+    val underPath = map.getAllDescendants("C://path").toSet()
+    assertEquals(setOf(10, 20, 30, 10, 43, 11, 21, 30, 11, 43, 13), underPath)
+    val underProto = map.getAllDescendants("C:/").toSet()
+    assertEquals(setOf(10, 20, 30, 10, 43, 11, 21, 30, 11, 43, 13), underProto)
+  }
+
+  @Test
+  fun `test usage with unix paths`() {
+    val map = PathPrefixTreeMapImpl<Int?>()
+    map["/path/to/my/dir1/"] = 10
+    map["/path/to/my/dir2"] = 20
+    map["/path/to/my/dir3/"] = 30
+    assertEquals(10, map.remove("/path/to/my/dir1/"))
+    assertEquals(null, map.remove("/path/to/my/dir1/"))
+    map["/path/to/my/dir4"] = 10
+    map["/path/to/dir1"] = 11
+    map["/path/to/dir2/"] = 21
+    assertEquals(11, map.remove("/path/to/dir1/"))
+    map["/path/to/dir3"] = 30
+    assertEquals(10, map.remove("/path/to/my/dir4/"))
+    map["/path/to/dir4/"] = 11
+    assertEquals(null, map.remove("/path"))
+    map["/path/to/my"] = 43
+    map["/path"] = 13
+    assertEquals(13, map.remove("/path"))
+    assertFalse(map.contains("/path/to/my/dir1"))
+    assertTrue(map.contains("/path/to/my/dir2"))
+    assertTrue(map.contains("/path/to/my/dir3"))
+    assertFalse(map.contains("/path/to/my/dir4/"))
+    assertFalse(map.contains("/path/to/dir1"))
+    assertTrue(map.contains("/path/to/dir2/"))
+    assertTrue(map.contains("/path/to/dir3"))
+    assertTrue(map.contains("/path/to/dir4/"))
+    assertTrue(map.contains("/path/to/my"))
+    assertFalse(map.contains("/path"))
+  }
+}
\ No newline at end of file
diff --git a/plugins/gradle/testSources/org/jetbrains/plugins/gradle/importing/GradleSettingsImportingTest.java b/plugins/gradle/testSources/org/jetbrains/plugins/gradle/importing/GradleSettingsImportingTest.java
index 10872dcec3fc..4f1c830c553f 100644
--- a/plugins/gradle/testSources/org/jetbrains/plugins/gradle/importing/GradleSettingsImportingTest.java
+++ b/plugins/gradle/testSources/org/jetbrains/plugins/gradle/importing/GradleSettingsImportingTest.java
@@ -417,7 +417,6 @@ public class GradleSettingsImportingTest extends GradleImportingTestCase {
 
   @Test
   public void testRemovingSourceFolderManagerMemLeaking() throws IOException {
-    refreshRecursively(myProjectRoot);
     SourceFolderManagerImpl sourceFolderManager = (SourceFolderManagerImpl)SourceFolderManager.getInstance(myProject);
     String javaSourcePath = FileUtil.toCanonicalPath(myProjectRoot.getPath() + "/java");
     String javaSourceUrl = VfsUtilCore.pathToUrl(javaSourcePath);
@@ -464,9 +463,6 @@ public class GradleSettingsImportingTest extends GradleImportingTestCase {
   @Ignore // Remove after published plugin ext with package prefix configuration
   @Test
   public void testPostponedImportPackagePrefix() throws IOException {
-    refreshRecursively(myProjectRoot);
-    ApplicationManager.getApplication().invokeAndWait(() -> {
-    });
     createProjectSubFile("src/main/java/Main.java", "");
     importProject(
       new GradleBuildScriptBuilderEx()
@@ -487,9 +483,6 @@ public class GradleSettingsImportingTest extends GradleImportingTestCase {
     assertSourceNotExists("project.main", "src/main/kotlin");
     assertSourceNotExists("project.test", "src/test/java");
     createProjectSubFile("src/main/kotlin/Main.kt", "");
-    refreshRecursively(myProjectRoot);
-    ApplicationManager.getApplication().invokeAndWait(() -> {
-    });
     assertSourcePackagePrefix("project.main", "src/main/java", "prefix.package.some");
     assertSourcePackagePrefix("project.main", "src/main/kotlin", "prefix.package.other");
     assertSourceNotExists("project.test", "src/test/java");