From 2f8a431a79b18bae0a2b75b9185c8320f57a0cc6 Mon Sep 17 00:00:00 2001
From: Ilya Gorbunov <ilya.gorbunov@jetbrains.com>
Date: Mon, 22 Jun 2015 20:50:05 +0300
Subject: [PATCH] Change getOrElse and getOrPut implementations so that double
 lookup is made when map doesn't contain value, rather when does.

---
 libraries/stdlib/src/kotlin/collections/Maps.kt | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/libraries/stdlib/src/kotlin/collections/Maps.kt b/libraries/stdlib/src/kotlin/collections/Maps.kt
index b8024001b31..2a694cc2aea 100644
--- a/libraries/stdlib/src/kotlin/collections/Maps.kt
+++ b/libraries/stdlib/src/kotlin/collections/Maps.kt
@@ -145,10 +145,11 @@ public fun <K, V> Map.Entry<K, V>.toPair(): Pair<K, V> {
  * @sample test.collections.MapTest.getOrElse
  */
 public inline fun <K, V> Map<K, V>.getOrElse(key: K, defaultValue: () -> V): V {
-    if (containsKey(key)) {
-        return get(key) as V
-    } else {
+    val value = get(key)
+    if (value == null && !containsKey(key)) {
         return defaultValue()
+    } else {
+        return value as V
     }
 }
 
@@ -159,12 +160,13 @@ public inline fun <K, V> Map<K, V>.getOrElse(key: K, defaultValue: () -> V): V {
  * @sample test.collections.MapTest.getOrPut
  */
 public inline fun <K, V> MutableMap<K, V>.getOrPut(key: K, defaultValue: () -> V): V {
-    if (containsKey(key)) {
-        return get(key) as V
-    } else {
+    val value = get(key)
+    if (value == null && !containsKey(key)) {
         val answer = defaultValue()
         put(key, answer)
         return answer
+    } else {
+        return value as V
     }
 }