Allow passing null parent directory to createTempFile/Directory

null signifies the default temp directory.

KT-19192

libraries/stdlib/jdk7/src/kotlin/io/path/PathUtils.kt

@@ -785,7 +785,7 @@ public inline fun Path.createFile(vararg attributes: FileAttribute<*>): Path =
  * @param attributes an optional list of file attributes to set atomically when creating the file.
  * @return the path to the newly created file that did not exist before.
  *
- * @throws  UnsupportedOperationException if the array contains an attribute that cannot be set atomically
+ * @throws UnsupportedOperationException if the array contains an attribute that cannot be set atomically
  *   when creating the file.
  *
  * @see Files.createTempFile
@@ -800,19 +800,23 @@ public inline fun createTempFile(prefix: String? = null, suffix: String? = null,
  * Creates an empty file in the specified [directory], using
  * the given [prefix] and [suffix] to generate its name.
  *
+ * @param directory the parent directory in which to create a new file.
+ *   It can be `null`, in that case the new file is created in the default temp directory.
  * @param attributes an optional list of file attributes to set atomically when creating the file.
  * @return the path to the newly created file that did not exist before.
  *
- * @throws  UnsupportedOperationException if the array contains an attribute that cannot be set atomically
+ * @throws UnsupportedOperationException if the array contains an attribute that cannot be set atomically
  *   when creating the file.
  *
  * @see Files.createTempFile
  */
 @SinceKotlin("1.4")
 @ExperimentalPathApi
-@kotlin.internal.InlineOnly
+public fun createTempFile(directory: Path?, prefix: String? = null, suffix: String? = null, vararg attributes: FileAttribute<*>): Path =
-public inline fun createTempFile(directory: Path, prefix: String? = null, suffix: String? = null, vararg attributes: FileAttribute<*>): Path =
+    if (directory != null)
-    Files.createTempFile(directory, prefix, suffix, *attributes)
+        Files.createTempFile(directory, prefix, suffix, *attributes)
+    else
+        Files.createTempFile(prefix, suffix, *attributes)
 
 /**
  * Creates a new directory in the default temp directory, using the given [prefix] to generate its name.
@@ -820,7 +824,7 @@ public inline fun createTempFile(directory: Path, prefix: String? = null, suffix
  * @param attributes an optional list of file attributes to set atomically when creating the directory.
  * @return the path to the newly created directory that did not exist before.
  *
- * @throws  UnsupportedOperationException if the array contains an attribute that cannot be set atomically
+ * @throws UnsupportedOperationException if the array contains an attribute that cannot be set atomically
  *   when creating the directory.
  *
  * @see Files.createTempDirectory
@@ -834,19 +838,23 @@ public inline fun createTempDirectory(prefix: String? = null, vararg attributes:
 /**
  * Creates a new directory in the specified [directory], using the given [prefix] to generate its name.
  *
+ * @param directory the parent directory in which to create a new directory.
+ *   It can be `null`, in that case the new directory is created in the default temp directory.
  * @param attributes an optional list of file attributes to set atomically when creating the directory.
  * @return the path to the newly created directory that did not exist before.
  *
- * @throws  UnsupportedOperationException if the array contains an attribute that cannot be set atomically
+ * @throws UnsupportedOperationException if the array contains an attribute that cannot be set atomically
  *   when creating the directory.
  *
  * @see Files.createTempDirectory
  */
 @SinceKotlin("1.4")
 @ExperimentalPathApi
-@kotlin.internal.InlineOnly
+public fun createTempDirectory(directory: Path?, prefix: String? = null, vararg attributes: FileAttribute<*>): Path =
-public inline fun createTempDirectory(directory: Path, prefix: String? = null, vararg attributes: FileAttribute<*>): Path =
+    if (directory != null)
-    Files.createTempDirectory(directory, prefix, *attributes)
+        Files.createTempDirectory(directory, prefix, *attributes)
+    else
+        Files.createTempDirectory(prefix, *attributes)
 
 /**
  * Resolves the given [other] path against this path.

libraries/stdlib/jdk7/test/PathExtensionsTest.kt

@@ -59,6 +59,24 @@ class PathExtensionsTest : AbstractPathTest() {
         assertFailsWith<FileAlreadyExistsException> { file.createFile() }
     }
 
+    @Test
+    fun createTempFileDefaultDir() {
+        val file1 = createTempFile().cleanup()
+        val file2 = createTempFile(directory = null).cleanup()
+
+        assertEquals(file1.parent, file2.parent)
+    }
+
+    @Test
+    fun createTempDirectoryDefaultDir() {
+        val dir1 = createTempDirectory().cleanup()
+        val dir2 = createTempDirectory(directory = null).cleanupRecursively()
+        val dir3 = createTempDirectory(dir2)
+
+        assertEquals(dir1.parent, dir2.parent)
+        assertNotEquals(dir2.parent, dir3.parent)
+    }
+
     @Test
     fun copyTo() {
         val root = createTempDirectory("copyTo-root").cleanupRecursively()

libraries/tools/binary-compatibility-validator/reference-public-api/kotlin-stdlib-jdk7.txt

@@ -4,6 +4,10 @@ public abstract interface annotation class kotlin/io/path/ExperimentalPathApi :
 public final class kotlin/io/path/PathsKt {
 	public static final fun appendText (Ljava/nio/file/Path;Ljava/lang/CharSequence;Ljava/nio/charset/Charset;)V
 	public static synthetic fun appendText$default (Ljava/nio/file/Path;Ljava/lang/CharSequence;Ljava/nio/charset/Charset;ILjava/lang/Object;)V
+	public static final fun createTempDirectory (Ljava/nio/file/Path;Ljava/lang/String;[Ljava/nio/file/attribute/FileAttribute;)Ljava/nio/file/Path;
+	public static synthetic fun createTempDirectory$default (Ljava/nio/file/Path;Ljava/lang/String;[Ljava/nio/file/attribute/FileAttribute;ILjava/lang/Object;)Ljava/nio/file/Path;
+	public static final fun createTempFile (Ljava/nio/file/Path;Ljava/lang/String;Ljava/lang/String;[Ljava/nio/file/attribute/FileAttribute;)Ljava/nio/file/Path;
+	public static synthetic fun createTempFile$default (Ljava/nio/file/Path;Ljava/lang/String;Ljava/lang/String;[Ljava/nio/file/attribute/FileAttribute;ILjava/lang/Object;)Ljava/nio/file/Path;
 	public static final fun fileAttributeViewNotAvailable (Ljava/nio/file/Path;Ljava/lang/Class;)Ljava/lang/Void;
 	public static final fun getExtension (Ljava/nio/file/Path;)Ljava/lang/String;
 	public static final fun getInvariantSeparatorsPath (Ljava/nio/file/Path;)Ljava/lang/String;