Sensible behavior for File.startsWith and File.endsWith

libraries/stdlib/src/kotlin/io/files/Utils.kt

@@ -379,14 +379,13 @@ public fun File.listFiles(filter: (file: File) -> Boolean): Array<File>? = listF
  * Determines whether this file belongs to the same root as [other]
  * and starts with all components of [other] in the same order.
  * So if [other] has N components, first N components of `this` must be the same as in [other].
- * For relative [other], `this` can belong to any root.
  *
  * @return `true` if this path starts with [other] path, `false` otherwise.
  */
 public fun File.startsWith(other: File): Boolean {
     val components = toComponents()
     val otherComponents = other.toComponents()
-    if (components.root != otherComponents.root && otherComponents.rootName != "")
+    if (components.root != otherComponents.root)
         return false
     return if (components.size < otherComponents.size) false
     else components.segments.subList(0, otherComponents.size).equals(otherComponents.segments)
@@ -396,25 +395,25 @@ public fun File.startsWith(other: File): Boolean {
  * Determines whether this file belongs to the same root as [other]
  * and starts with all components of [other] in the same order.
  * So if [other] has N components, first N components of `this` must be the same as in [other].
- * For relative [other], `this` can belong to any root.
  *
  * @return `true` if this path starts with [other] path, `false` otherwise.
  */
 public fun File.startsWith(other: String): Boolean = startsWith(File(other))
 
 /**
- * Determines whether this file belongs to the same root as [other]
+ * Determines whether this file path ends with the path of [other] file.
- * and ends with all components of [other] in the same order.
+ *
- * So if [other] has N components, last N components of `this` must be the same as in [other].
+ * If [other] is rooted path it must be equal to this.
- * For relative [other], `this` can belong to any root.
+ * If [other] is relative path then last N components of `this` must be the same as all components in [other],
+ * where N is the number of components in [other].
  *
  * @return `true` if this path ends with [other] path, `false` otherwise.
  */
 public fun File.endsWith(other: File): Boolean {
     val components = toComponents()
     val otherComponents = other.toComponents()
-    if (components.root != otherComponents.root && otherComponents.rootName != "")
+    if (otherComponents.isRooted)
-        return false
+        return this == other
     val shift = components.size - otherComponents.size
     return if (shift < 0) false
     else components.segments.subList(shift, components.size).equals(otherComponents.segments)

libraries/stdlib/test/io/Files.kt

@@ -243,8 +243,8 @@ class FilesTest {
         assertTrue(File("/foo/bar").startsWith(File("/foo/bar")))
         assertTrue(File("/foo/bar").startsWith(File("/foo")))
         assertTrue(File("/foo/bar").startsWith("/"))
-// TODO: assertFalse(File("/foo/bar").startsWith(""))
+        assertFalse(File("/foo/bar").startsWith(""))
-// TODO: assertFalse(File("/foo/bar").startsWith(File("foo")))
+        assertFalse(File("/foo/bar").startsWith(File("foo")))
         assertFalse(File("/foo/bar").startsWith("/fo"))
 
         if (isBackslashSeparator) {
@@ -259,9 +259,15 @@ class FilesTest {
 
     @test fun endsWith() {
         assertTrue(File("/foo/bar").endsWith("bar"))
-        assertTrue(File("/foo/bar").endsWith("/bar"))
+        assertTrue(File("/foo/bar").endsWith("foo/bar"))
-        assertTrue(File("/foo/bar/gav/bar").endsWith("/bar"))
+        assertTrue(File("/foo/bar").endsWith("/foo/bar"))
-        assertTrue(File("/foo/bar/gav/bar").endsWith("/gav/bar"))
+        assertTrue(File("foo/bar").endsWith("foo/bar"))
+        assertTrue(File("foo/bar").endsWith("bar/"))
+
+        assertFalse(File("/foo/bar").endsWith("ar"))
+        assertFalse(File("/foo/bar").endsWith("/bar"))
+        assertFalse(File("/foo/bar/gav/bar").endsWith("/bar"))
+        assertFalse(File("/foo/bar/gav/bar").endsWith("/gav/bar"))
         assertFalse(File("/foo/bar/gav").endsWith("/bar"))
         assertFalse(File("foo/bar").endsWith("/bar"))
         if (isCaseInsensitiveFileSystem) {