DX-122953 Complete empty large list split transfer

Author: prashanthbdremio

vector/src/main/java/org/apache/arrow/vector/complex/LargeListVector.java

@@ -686,24 +686,30 @@ public void splitAndTransfer(int startIndex, int length) {
           startIndex,
           length,
           valueCount);
-      final long startPoint = offsetBuffer.getLong((long) startIndex * OFFSET_WIDTH);
-      final long sliceLength =
-          offsetBuffer.getLong((long) (startIndex + length) * OFFSET_WIDTH) - startPoint;
       to.clear();
-      to.offsetBuffer = to.allocateOffsetBuffer((length + 1) * OFFSET_WIDTH);
-      /* splitAndTransfer offset buffer */
-      for (int i = 0; i < length + 1; i++) {
-        final long relativeOffset =
-            offsetBuffer.getLong((long) (startIndex + i) * OFFSET_WIDTH) - startPoint;
-        to.offsetBuffer.setLong((long) i * OFFSET_WIDTH, relativeOffset);
+      if (length > 0) {
+        final long startPoint = offsetBuffer.getLong((long) startIndex * OFFSET_WIDTH);
+        final long sliceLength =
+            offsetBuffer.getLong((long) (startIndex + length) * OFFSET_WIDTH) - startPoint;
+        to.offsetBuffer = to.allocateOffsetBuffer((length + 1) * OFFSET_WIDTH);
+        /* splitAndTransfer offset buffer */
+        for (int i = 0; i < length + 1; i++) {
+          final long relativeOffset =
+              offsetBuffer.getLong((long) (startIndex + i) * OFFSET_WIDTH) - startPoint;
+          to.offsetBuffer.setLong((long) i * OFFSET_WIDTH, relativeOffset);
+        }
+        /* splitAndTransfer validity buffer */
+        splitAndTransferValidityBuffer(startIndex, length, to);
+        /* splitAndTransfer data buffer */
+        dataTransferPair.splitAndTransfer(
+            checkedCastToInt(startPoint), checkedCastToInt(sliceLength));
+        to.lastSet = length - 1;
+        to.setValueCount(length);
+      } else {
+        to.ensureEmptyOffsetBufferCapacity(OFFSET_WIDTH);
+        dataTransferPair.splitAndTransfer(0, 0);
+        to.setValueCount(0);
       }
-      /* splitAndTransfer validity buffer */
-      splitAndTransferValidityBuffer(startIndex, length, to);
-      /* splitAndTransfer data buffer */
-      dataTransferPair.splitAndTransfer(
-          checkedCastToInt(startPoint), checkedCastToInt(sliceLength));
-      to.lastSet = length - 1;
-      to.setValueCount(length);
     }
 
     /*

vector/src/test/java/org/apache/arrow/vector/TestSplitAndTransfer.java

@@ -34,6 +34,7 @@
 import org.apache.arrow.vector.complex.BaseRepeatedValueVector;
 import org.apache.arrow.vector.complex.DenseUnionVector;
 import org.apache.arrow.vector.complex.FixedSizeListVector;
+import org.apache.arrow.vector.complex.LargeListVector;
 import org.apache.arrow.vector.complex.LargeListViewVector;
 import org.apache.arrow.vector.complex.ListVector;
 import org.apache.arrow.vector.complex.MapVector;
@@ -944,6 +945,29 @@ public void testLargeListViewVectorZeroStartIndexAndLength() {
     }
   }
 
+  @Test
+  public void testLargeListVectorZeroStartIndexAndLength() {
+    try (final LargeListVector listVector = LargeListVector.empty("largelist", allocator);
+        final LargeListVector newListVector = LargeListVector.empty("newList", allocator)) {
+
+      listVector.allocateNew();
+      final int valueCount = 0;
+      listVector.setValueCount(valueCount);
+
+      final TransferPair tp = listVector.makeTransferPair(newListVector);
+
+      tp.splitAndTransfer(0, 0);
+      assertEquals(valueCount, newListVector.getValueCount());
+      List<ArrowBuf> buffers = newListVector.getFieldBuffers();
+      ArrowBuf offsetBuffer = buffers.get(1);
+      assertEquals(LargeListVector.OFFSET_WIDTH, offsetBuffer.readableBytes());
+      assertTrue(offsetBuffer.capacity() >= LargeListVector.OFFSET_WIDTH);
+      assertEquals(0L, offsetBuffer.getLong(0));
+
+      newListVector.clear();
+    }
+  }
+
   @Test
   public void testStructVectorZeroStartIndexAndLength() {
     Map<String, String> metadata = new HashMap<>();