From 1d18389e32e8afdbf5caa89808fb5af308fb5c8d Mon Sep 17 00:00:00 2001
From: Matthew Pope <popematt@amazon.com>
Date: Wed, 20 Mar 2024 14:17:57 -0700
Subject: [PATCH] Adds an empty input check to all addAll, removeAll, and
 retainAll methods

---
 .../implementations/immutableList/AbstractPersistentList.kt | 6 ++++++
 .../immutableList/PersistentVectorBuilder.kt                | 1 +
 .../src/implementations/immutableMap/PersistentHashMap.kt   | 1 +
 .../immutableMap/PersistentHashMapBuilder.kt                | 1 +
 .../src/implementations/immutableSet/PersistentHashSet.kt   | 3 +++
 .../immutableSet/PersistentHashSetBuilder.kt                | 2 ++
 .../persistentOrderedMap/PersistentOrderedMap.kt            | 1 +
 .../persistentOrderedSet/PersistentOrderedSet.kt            | 3 +++
 8 files changed, 18 insertions(+)

diff --git a/core/commonMain/src/implementations/immutableList/AbstractPersistentList.kt b/core/commonMain/src/implementations/immutableList/AbstractPersistentList.kt
index e018fe4e..525e59b5 100644
--- a/core/commonMain/src/implementations/immutableList/AbstractPersistentList.kt
+++ b/core/commonMain/src/implementations/immutableList/AbstractPersistentList.kt
@@ -8,6 +8,7 @@ package kotlinx.collections.immutable.implementations.immutableList
 import kotlinx.collections.immutable.ImmutableList
 import kotlinx.collections.immutable.PersistentList
 import kotlinx.collections.immutable.mutate
+import kotlinx.collections.immutable.internal.ListImplementation.checkPositionIndex
 
 public abstract class AbstractPersistentList<E> : PersistentList<E>, AbstractList<E>() {
     override fun subList(fromIndex: Int, toIndex: Int): ImmutableList<E> {
@@ -15,10 +16,13 @@ public abstract class AbstractPersistentList<E> : PersistentList<E>, AbstractLis
     }
 
     override fun addAll(elements: Collection<E>): PersistentList<E> {
+        if (elements.isEmpty()) return this
         return mutate { it.addAll(elements) }
     }
 
     override fun addAll(index: Int, c: Collection<E>): PersistentList<E> {
+        checkPositionIndex(index, size)
+        if (c.isEmpty()) return this
         return mutate { it.addAll(index, c) }
     }
 
@@ -31,10 +35,12 @@ public abstract class AbstractPersistentList<E> : PersistentList<E>, AbstractLis
     }
 
     override fun removeAll(elements: Collection<E>): PersistentList<E> {
+        if (elements.isEmpty()) return this
         return removeAll { elements.contains(it) }
     }
 
     override fun retainAll(elements: Collection<E>): PersistentList<E> {
+        if (elements.isEmpty()) return persistentVectorOf()
         return removeAll { !elements.contains(it) }
     }
 
diff --git a/core/commonMain/src/implementations/immutableList/PersistentVectorBuilder.kt b/core/commonMain/src/implementations/immutableList/PersistentVectorBuilder.kt
index 6d788ab5..f4f56f71 100644
--- a/core/commonMain/src/implementations/immutableList/PersistentVectorBuilder.kt
+++ b/core/commonMain/src/implementations/immutableList/PersistentVectorBuilder.kt
@@ -669,6 +669,7 @@ internal class PersistentVectorBuilder<E>(private var vector: PersistentList<E>,
     }
 
     override fun removeAll(elements: Collection<E>): Boolean {
+        if (elements.isEmpty()) return false
         return removeAllWithPredicate { elements.contains(it) }
     }
 
diff --git a/core/commonMain/src/implementations/immutableMap/PersistentHashMap.kt b/core/commonMain/src/implementations/immutableMap/PersistentHashMap.kt
index 332e5e40..e798d483 100644
--- a/core/commonMain/src/implementations/immutableMap/PersistentHashMap.kt
+++ b/core/commonMain/src/implementations/immutableMap/PersistentHashMap.kt
@@ -68,6 +68,7 @@ internal class PersistentHashMap<K, V>(internal val node: TrieNode<K, V>,
     }
 
     override fun putAll(m: Map<out K, @UnsafeVariance V>): PersistentMap<K, V> {
+        if (m.isEmpty()) return this
         return this.mutate { it.putAll(m) }
     }
 
diff --git a/core/commonMain/src/implementations/immutableMap/PersistentHashMapBuilder.kt b/core/commonMain/src/implementations/immutableMap/PersistentHashMapBuilder.kt
index 983a319f..eac1cac9 100644
--- a/core/commonMain/src/implementations/immutableMap/PersistentHashMapBuilder.kt
+++ b/core/commonMain/src/implementations/immutableMap/PersistentHashMapBuilder.kt
@@ -66,6 +66,7 @@ internal class PersistentHashMapBuilder<K, V>(private var map: PersistentHashMap
     }
 
     override fun putAll(from: Map<out K, V>) {
+        if (from.isEmpty()) return
         val map = from as? PersistentHashMap ?: (from as? PersistentHashMapBuilder)?.build()
         if (map != null) @Suppress("UNCHECKED_CAST") {
             val intersectionCounter = DeltaCounter()
diff --git a/core/commonMain/src/implementations/immutableSet/PersistentHashSet.kt b/core/commonMain/src/implementations/immutableSet/PersistentHashSet.kt
index 8686b1ee..7ac2a461 100644
--- a/core/commonMain/src/implementations/immutableSet/PersistentHashSet.kt
+++ b/core/commonMain/src/implementations/immutableSet/PersistentHashSet.kt
@@ -21,6 +21,7 @@ internal class PersistentHashSet<E>(internal val node: TrieNode<E>,
     }
 
     override fun addAll(elements: Collection<E>): PersistentSet<E> {
+        if (elements.isEmpty()) return this
         return this.mutate { it.addAll(elements) }
     }
 
@@ -31,6 +32,7 @@ internal class PersistentHashSet<E>(internal val node: TrieNode<E>,
     }
 
     override fun removeAll(elements: Collection<E>): PersistentSet<E> {
+        if (elements.isEmpty()) return this
         return mutate { it.removeAll(elements) }
     }
 
@@ -39,6 +41,7 @@ internal class PersistentHashSet<E>(internal val node: TrieNode<E>,
     }
 
     override fun retainAll(elements: Collection<E>): PersistentSet<E> {
+        if (elements.isEmpty()) return PersistentHashSet.emptyOf<E>()
         return mutate { it.retainAll(elements) }
     }
 
diff --git a/core/commonMain/src/implementations/immutableSet/PersistentHashSetBuilder.kt b/core/commonMain/src/implementations/immutableSet/PersistentHashSetBuilder.kt
index a9bce437..a5899156 100644
--- a/core/commonMain/src/implementations/immutableSet/PersistentHashSetBuilder.kt
+++ b/core/commonMain/src/implementations/immutableSet/PersistentHashSetBuilder.kt
@@ -45,6 +45,7 @@ internal class PersistentHashSetBuilder<E>(private var set: PersistentHashSet<E>
     }
 
     override fun addAll(elements: Collection<E>): Boolean {
+        if (elements.isEmpty()) return false
         val set = elements as? PersistentHashSet ?: (elements as? PersistentHashSetBuilder)?.build()
         if (set !== null) {
             val deltaCounter = DeltaCounter()
@@ -81,6 +82,7 @@ internal class PersistentHashSetBuilder<E>(private var set: PersistentHashSet<E>
     }
 
     override fun removeAll(elements: Collection<E>): Boolean {
+        if (elements.isEmpty()) return false
         val set = elements as? PersistentHashSet ?: (elements as? PersistentHashSetBuilder)?.build()
         if (set !== null) {
             val counter = DeltaCounter()
diff --git a/core/commonMain/src/implementations/persistentOrderedMap/PersistentOrderedMap.kt b/core/commonMain/src/implementations/persistentOrderedMap/PersistentOrderedMap.kt
index 94d25929..5f7df084 100644
--- a/core/commonMain/src/implementations/persistentOrderedMap/PersistentOrderedMap.kt
+++ b/core/commonMain/src/implementations/persistentOrderedMap/PersistentOrderedMap.kt
@@ -117,6 +117,7 @@ internal class PersistentOrderedMap<K, V>(
     }
 
     override fun putAll(m: Map<out K, @UnsafeVariance V>): PersistentMap<K, V> {
+        if (m.isEmpty()) return this
         return this.mutate { it.putAll(m) }
     }
 
diff --git a/core/commonMain/src/implementations/persistentOrderedSet/PersistentOrderedSet.kt b/core/commonMain/src/implementations/persistentOrderedSet/PersistentOrderedSet.kt
index a1f5dc1a..54bc6e72 100644
--- a/core/commonMain/src/implementations/persistentOrderedSet/PersistentOrderedSet.kt
+++ b/core/commonMain/src/implementations/persistentOrderedSet/PersistentOrderedSet.kt
@@ -53,6 +53,7 @@ internal class PersistentOrderedSet<E>(
     }
 
     override fun addAll(elements: Collection<E>): PersistentSet<E> {
+        if (elements.isEmpty()) return this
         return this.mutate { it.addAll(elements) }
     }
 
@@ -78,6 +79,7 @@ internal class PersistentOrderedSet<E>(
     }
 
     override fun removeAll(elements: Collection<E>): PersistentSet<E> {
+        if (elements.isEmpty()) return this
         return mutate { it.removeAll(elements) }
     }
 
@@ -86,6 +88,7 @@ internal class PersistentOrderedSet<E>(
     }
 
     override fun retainAll(elements: Collection<E>): PersistentSet<E> {
+        if (elements.isEmpty()) return PersistentOrderedSet.emptyOf<E>()
         return mutate { it.retainAll(elements) }
     }