Merge pull request real-logic#125 from menski/fix-IntArrayList-addInt

[Java] Use current size for array copy in IntArrayList
isabella232 · Jan 16, 2018 · f6e40e3 · f6e40e3
2 parents bc6bd50 + 81507d0
commit f6e40e3
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Showing 2 changed files with 15 additions and 1 deletion.
diff --git a/agrona/src/main/java/org/agrona/collections/IntArrayList.java b/agrona/src/main/java/org/agrona/collections/IntArrayList.java
@@ -209,7 +209,7 @@ public void addInt(
 
         if (index < size)
         {
-            System.arraycopy(elements, index, elements, index + 1, requiredSize - index);
+            System.arraycopy(elements, index, elements, index + 1, size - index);
         }
 
         elements[index] = element;

diff --git a/agrona/src/test/java/org/agrona/collections/IntArrayListTest.java b/agrona/src/test/java/org/agrona/collections/IntArrayListTest.java
@@ -77,6 +77,20 @@ public void shouldAddValueAtIndex()
         assertThat(list.getInt(count), is(count - 1));
     }
 
+    @Test
+    public void shouldAddValueAtIndexWithNearlyFullCapacity()
+    {
+        final int count = IntArrayList.INITIAL_CAPACITY - 1;
+        final int value = count + 1;
+        IntStream.range(0, count).forEachOrdered(list::addInt);
+
+        list.addInt(0, value);
+
+        assertThat(list.size(), is(count + 1));
+        assertThat(list.getInt(0), is(value));
+        assertThat(list.getInt(count), is(count - 1));
+    }
+
     @Test
     public void shouldSetIntValue()
     {