(commons-collections) branch master updated: Move argument check deeper in.

[ggregory]

This is an automated email from the ASF dual-hosted git repository.

ggregory pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-collections.git


The following commit(s) were added to refs/heads/master by this push:
     new 99c8a4d11 Move argument check deeper in.
99c8a4d11 is described below

commit 99c8a4d11823b554ea9a28015d224ae8bdd4224a
Author: Gary Gregory <garydgreg...@gmail.com>
AuthorDate: Thu Jan 15 12:31:44 2026 -0500

    Move argument check deeper in.
---
 .../apache/commons/collections4/list/TreeList.java | 25 ++++++++++++++++------
 .../commons/collections4/list/TreeListTest.java    | 12 +++++++++++
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/src/main/java/org/apache/commons/collections4/list/TreeList.java 
b/src/main/java/org/apache/commons/collections4/list/TreeList.java
index a0e1c7145..57c15b24e 100644
--- a/src/main/java/org/apache/commons/collections4/list/TreeList.java
+++ b/src/main/java/org/apache/commons/collections4/list/TreeList.java
@@ -804,6 +804,7 @@ public class TreeList<E> extends AbstractList<E> {
          * @param fromIndex  the index to start at
          */
         protected TreeListIterator(final TreeList<E> parent, final int 
fromIndex) {
+            checkInterval(fromIndex, 0, parent.size(), parent.size());
             this.parent = parent;
             this.expectedModCount = parent.modCount;
             this.next = parent.root == null ? null : 
parent.root.get(fromIndex);
@@ -916,6 +917,21 @@ public class TreeList<E> extends AbstractList<E> {
         }
     }
 
+    /**
+     * Checks whether the index is valid.
+     *
+     * @param index  the index to check.
+     * @param startIndex  the first allowed index.
+     * @param endIndex  the last allowed index.
+     * @param endIndex  the size.
+     * @throws IndexOutOfBoundsException if the index is invalid
+     */
+    private static void checkInterval(final int index, final int startIndex, 
final int endIndex, final int size) {
+        if (index < startIndex || index > endIndex) {
+            throw new IndexOutOfBoundsException("Invalid index:" + index + ", 
size=" + size);
+        }
+    }
+
     /** The root node in the AVL tree */
     private AVLNode<E> root;
 
@@ -994,9 +1010,7 @@ public class TreeList<E> extends AbstractList<E> {
      * @throws IndexOutOfBoundsException if the index is invalid
      */
     private void checkInterval(final int index, final int startIndex, final 
int endIndex) {
-        if (index < startIndex || index > endIndex) {
-            throw new IndexOutOfBoundsException("Invalid index:" + index + ", 
size=" + size());
-        }
+        checkInterval(index, startIndex, endIndex, size());
     }
 
     /**
@@ -1072,14 +1086,13 @@ public class TreeList<E> extends AbstractList<E> {
     /**
      * Gets a ListIterator over the list.
      *
-     * @param fromIndex  the index to start from
-     * @return the new iterator
+     * @param fromIndex  the index to start from.
+     * @return the new iterator.
      */
     @Override
     public ListIterator<E> listIterator(final int fromIndex) {
         // override to go 75% faster
         // cannot use EmptyIterator as iterator.add() must work
-        checkInterval(fromIndex, 0, size());
         return new TreeListIterator<>(this, fromIndex);
     }
 
diff --git 
a/src/test/java/org/apache/commons/collections4/list/TreeListTest.java 
b/src/test/java/org/apache/commons/collections4/list/TreeListTest.java
index ec5b683e6..1f502208e 100644
--- a/src/test/java/org/apache/commons/collections4/list/TreeListTest.java
+++ b/src/test/java/org/apache/commons/collections4/list/TreeListTest.java
@@ -19,6 +19,7 @@ package org.apache.commons.collections4.list;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -100,6 +101,17 @@ public class TreeListTest<E> extends AbstractListTest<E> {
         return new TreeList<>();
     }
 
+    @Test
+    void testPreviousNullPointerException() throws Throwable {
+        final TreeList<String> treeList = new TreeList<>();
+        treeList.add("a");
+        treeList.add("b");
+        assertThrows(IndexOutOfBoundsException.class, () -> 
treeList.listIterator(3).previous());
+        assertThrows(IndexOutOfBoundsException.class, () -> new 
TreeList.TreeListIterator<String>(treeList, 3));
+        // Test doesn't get to previous()
+        assertThrows(IndexOutOfBoundsException.class, () -> new 
TreeList.TreeListIterator<String>(treeList, 3).previous());
+    }
+
     @Test
     @SuppressWarnings("unchecked")
     void testAddMultiple() {