From 3dd195574954a3effd750cd07f460ceb1823bc0b Mon Sep 17 00:00:00 2001
From: Andreas Huber <bitbucket@lucares.de>
Date: Sat, 9 Dec 2017 15:50:55 +0100
Subject: [PATCH] indexOf on sorted lists should return the first match

---
 .../src/main/java/org/lucares/collections/IntList.java     | 6 ++++--
 .../src/test/java/org/lucares/collections/IntListTest.java | 7 +++++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/primitiveCollections/src/main/java/org/lucares/collections/IntList.java b/primitiveCollections/src/main/java/org/lucares/collections/IntList.java
index 33a4096..c052647 100644
--- a/primitiveCollections/src/main/java/org/lucares/collections/IntList.java
+++ b/primitiveCollections/src/main/java/org/lucares/collections/IntList.java
@@ -616,7 +616,10 @@ public final class IntList implements Serializable, Cloneable {
 
 		int result = -1;
 		if (sorted) {
-			final int insertionPoint = Arrays.binarySearch(data, offset, size(), value);
+			int insertionPoint = Arrays.binarySearch(data, offset, size(), value);
+			while (insertionPoint > 0 && insertionPoint > offset && data[insertionPoint - 1] == value) {
+				insertionPoint--;
+			}
 			result = insertionPoint < 0 ? -1 : insertionPoint;
 		} else {
 			for (int i = offset; i < size; i++) {
@@ -867,5 +870,4 @@ public final class IntList implements Serializable, Cloneable {
 
 		return result;
 	}
-
 }
diff --git a/primitiveCollections/src/test/java/org/lucares/collections/IntListTest.java b/primitiveCollections/src/test/java/org/lucares/collections/IntListTest.java
index bb107a3..8dcd967 100644
--- a/primitiveCollections/src/test/java/org/lucares/collections/IntListTest.java
+++ b/primitiveCollections/src/test/java/org/lucares/collections/IntListTest.java
@@ -680,6 +680,13 @@ public class IntListTest {
 		Assert.assertEquals(1, list.indexOf(2));
 	}
 
+	@Test
+	public void testIndexOfOnSortedListReturnsFirstMatch() {
+		final IntList list = IntList.of(0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 4);
+		Assert.assertEquals(2, list.indexOf(2));
+		Assert.assertEquals(4, list.indexOf(2, 4));
+	}
+
 	@Test
 	public void testIndexOfOnUnsortedList() {
 		final IntList list = IntList.of(2, 0, 1);