Fix intege overflow in _setBooleanElement in a primitive list

runtime/src/main/java/org/capnproto/ListBuilder.java

@@ -99,7 +99,7 @@ public class ListBuilder extends CapTableBuilder.BuilderContext {
     }
 
     protected void _setBooleanElement(int index, boolean value) {
-        long bitOffset = index * this.step;
+        long bitOffset = (long) index * this.step;
         byte bitnum = (byte)(bitOffset % 8);
         int position = (int)(this.ptr + (bitOffset / 8));
         byte oldValue = this.segment.buffer.get(position);

runtime/src/test/java/org/capnproto/ListBuilderTest.java

@@ -0,0 +1,18 @@
+package org.capnproto;
+
+import org.junit.Test;
+
+import java.nio.ByteBuffer;
+
+public class ListBuilderTest {
+
+    @Test(expected = IndexOutOfBoundsException.class)
+    public void _setBooleanElementShouldNotOverflowDuringPositionOffsetCalculation() {
+        ByteBuffer buffer = ByteBuffer.allocate(10);
+        BuilderArena builderArena = new BuilderArena(new DefaultAllocator());
+        SegmentBuilder segmentBuilder = new SegmentBuilder(buffer, builderArena);
+        ListBuilder listBuilder = new ListBuilder(segmentBuilder, 0, 0, 2, 0, (short) 0);
+
+        listBuilder._setBooleanElement(Integer.MAX_VALUE, true);
+    }
+}