From 036bbf34d2742af78ff2c44f4223e1b268e1c12c Mon Sep 17 00:00:00 2001
From: Gary Gregory <gardgregory@gmail.com>
Date: Sat, 9 Feb 2019 17:52:29 -0500
Subject: [PATCH] [COLLECTIONS-710] Calling CompositeCollection.size() will
 cash if the list contains null element.

---
 .../collections4/set/CompositeSet.java        | 37 +++++++++++--------
 .../collections4/set/CompositeSetTest.java    | 16 ++++++++
 2 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/src/main/java/org/apache/commons/collections4/set/CompositeSet.java b/src/main/java/org/apache/commons/collections4/set/CompositeSet.java
index b8f93f804..4ba735708 100644
--- a/src/main/java/org/apache/commons/collections4/set/CompositeSet.java
+++ b/src/main/java/org/apache/commons/collections4/set/CompositeSet.java
@@ -252,6 +252,9 @@ public class CompositeSet<E> implements Set<E>, Serializable {
      */
     @Override
     public boolean containsAll(final Collection<?> coll) {
+        if (coll == null) {
+            return false;
+        }
         for (final Object item : coll) {
             if (contains(item) == false) {
                 return false;
@@ -291,7 +294,7 @@ public class CompositeSet<E> implements Set<E>, Serializable {
      */
     @Override
     public boolean removeAll(final Collection<?> coll) {
-        if (coll.size() == 0) {
+        if (CollectionUtils.isEmpty(coll)) {
             return false;
         }
         boolean changed = false;
@@ -354,21 +357,23 @@ public class CompositeSet<E> implements Set<E>, Serializable {
      * @see SetMutator
      */
     public synchronized void addComposited(final Set<E> set) {
-        for (final Set<E> existingSet : getSets()) {
-            final Collection<E> intersects = CollectionUtils.intersection(existingSet, set);
-            if (intersects.size() > 0) {
-                if (this.mutator == null) {
-                    throw new UnsupportedOperationException(
-                        "Collision adding composited set with no SetMutator set");
-                }
-                getMutator().resolveCollision(this, existingSet, set, intersects);
-                if (CollectionUtils.intersection(existingSet, set).size() > 0) {
-                    throw new IllegalArgumentException(
-                        "Attempt to add illegal entry unresolved by SetMutator.resolveCollision()");
+        if (set != null) {
+            for (final Set<E> existingSet : getSets()) {
+                final Collection<E> intersects = CollectionUtils.intersection(existingSet, set);
+                if (intersects.size() > 0) {
+                    if (this.mutator == null) {
+                        throw new UnsupportedOperationException(
+                                "Collision adding composited set with no SetMutator set");
+                    }
+                    getMutator().resolveCollision(this, existingSet, set, intersects);
+                    if (CollectionUtils.intersection(existingSet, set).size() > 0) {
+                        throw new IllegalArgumentException(
+                                "Attempt to add illegal entry unresolved by SetMutator.resolveCollision()");
+                    }
                 }
             }
+            all.add(set);
         }
-        all.add(set);
     }
 
     /**
@@ -388,8 +393,10 @@ public class CompositeSet<E> implements Set<E>, Serializable {
      * @param sets  the Sets to be appended to the composite
      */
     public void addComposited(final Set<E>... sets) {
-        for (final Set<E> set : sets) {
-            addComposited(set);
+        if (sets != null) {
+            for (final Set<E> set : sets) {
+                addComposited(set);
+            }
         }
     }
 
diff --git a/src/test/java/org/apache/commons/collections4/set/CompositeSetTest.java b/src/test/java/org/apache/commons/collections4/set/CompositeSetTest.java
index 83618c393..1d38694f3 100644
--- a/src/test/java/org/apache/commons/collections4/set/CompositeSetTest.java
+++ b/src/test/java/org/apache/commons/collections4/set/CompositeSetTest.java
@@ -64,6 +64,18 @@ public class CompositeSetTest<E> extends AbstractSetTest<E> {
         assertTrue(set.contains("1"));
     }
 
+    @SuppressWarnings("unchecked")
+    public void testContainsAll() {
+        final CompositeSet<E> set = new CompositeSet<>(new Set[]{ buildOne(), buildTwo() });
+        assertFalse(set.containsAll(null));
+    }
+
+    @SuppressWarnings("unchecked")
+    public void testRemoveAll() {
+        final CompositeSet<E> set = new CompositeSet<>(new Set[]{ buildOne(), buildTwo() });
+        assertFalse(set.removeAll(null));
+    }
+
     @SuppressWarnings("unchecked")
     public void testRemoveUnderlying() {
         final Set<E> one = buildOne();
@@ -132,6 +144,10 @@ public class CompositeSetTest<E> extends AbstractSetTest<E> {
         final Set<E> two = buildTwo();
         final CompositeSet<E> set = new CompositeSet<>();
         set.addComposited(one, two);
+        set.addComposited((Set<E>) null);
+        set.addComposited((Set<E>[]) null);
+        set.addComposited(null, null);
+        set.addComposited(null, null, null);
         final CompositeSet<E> set2 = new CompositeSet<>(buildOne());
         set2.addComposited(buildTwo());
         assertTrue(set.equals(set2));