From 0e85fdd2cf2ea73c0d2537905f03d119634733da Mon Sep 17 00:00:00 2001
From: Evgeny Gerashchenko <Evgeny.Gerashchenko@jetbrains.com>
Date: Fri, 1 Mar 2013 23:28:09 +0400
Subject: [PATCH] KT-3290 File.recurse NPE

 #KT-3290 fixed
---
 libraries/stdlib/src/kotlin/io/Files.kt |  5 +++--
 libraries/stdlib/test/IoTest.kt         | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/libraries/stdlib/src/kotlin/io/Files.kt b/libraries/stdlib/src/kotlin/io/Files.kt
index c246bb76856..6061e0d2201 100644
--- a/libraries/stdlib/src/kotlin/io/Files.kt
+++ b/libraries/stdlib/src/kotlin/io/Files.kt
@@ -12,8 +12,9 @@ import java.net.URL
  */
 public fun File.recurse(block: (File) -> Unit): Unit {
     block(this)
-    if (this.isDirectory()) {
-        for (child in this.listFiles()!!) {
+    val children = this.listFiles()
+    if (children != null) {
+        for (child in children) {
             child.recurse(block)
         }
     }
diff --git a/libraries/stdlib/test/IoTest.kt b/libraries/stdlib/test/IoTest.kt
index c881be4363b..f85616c6221 100644
--- a/libraries/stdlib/test/IoTest.kt
+++ b/libraries/stdlib/test/IoTest.kt
@@ -110,4 +110,29 @@ class IoTest(){
         assertEquals("", file1.relativePath(file1))
         assertEquals(file3.canonicalPath, file1.relativePath(file3))
     }
+
+    test fun listFiles() {
+        val dir = File.createTempFile("temp", System.nanoTime().toString())
+        dir.delete()
+        dir.mkdir()
+
+        File.createTempFile("temp", "1.kt", dir)
+        File.createTempFile("temp", "2.java", dir)
+
+        val subdir = File(dir, "subdir")
+        subdir.mkdir()
+
+        File(subdir, "3.txt").createNewFile()
+
+        var totalFiles = 0
+        dir.recurse { totalFiles++ }
+
+        assertEquals(5, totalFiles)
+
+        subdir.setReadable(false)
+
+        var totalFilesWithUnReadableDir = 0
+        dir.recurse { totalFilesWithUnReadableDir++ }
+        assertEquals(4, totalFilesWithUnReadableDir)
+    }
 }