fix(vector): reallocate LargeListVector offsets that cannot hold [0]

A zero-length split of a ListVector only clears its target, so a
LargeListVector below it keeps the allocator's shared empty buffer as
its offsets. getFieldBuffers() then set the writer index of the shared
buffer to 8: the LargeList offsets were written with no bytes when a
later vector reset it, and when none did, every other buffer still on
the shared empty buffer was sized 8 bytes and writing the batch threw
IndexOutOfBoundsException.

Reallocate the offsets buffer in getFieldBuffers() when it cannot hold
[0], as ListVector now does.

Author: jbonofre

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

@@ -316,7 +316,18 @@ private void setReaderAndWriterIndex() {
     // Both are set to 0 means 0 bytes are written to the IPC stream which will crash IPC readers
     // in other libraries. According to Arrow spec, we should still output the offset buffer which
     // is [0].
-    offsetBuffer.writerIndex((long) (valueCount + 1) * OFFSET_WIDTH);
+    final long requiredOffsetBufferSize = (long) (valueCount + 1) * OFFSET_WIDTH;
+    if (offsetBuffer.capacity() < requiredOffsetBufferSize) {
+      // An empty vector may still hold the allocator's shared empty buffer
+      ArrowBuf newOffsetBuffer = allocator.buffer(requiredOffsetBufferSize);
+      newOffsetBuffer.setZero(0, newOffsetBuffer.capacity());
+      if (offsetBuffer.capacity() > 0) {
+        newOffsetBuffer.setBytes(0, offsetBuffer, 0, offsetBuffer.capacity());
+      }
+      offsetBuffer.getReferenceManager().release();
+      offsetBuffer = newOffsetBuffer;
+    }
+    offsetBuffer.writerIndex(requiredOffsetBufferSize);
   }
 
   /**

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

@@ -1216,4 +1216,17 @@ public void testSetValueCountAcceptsMaxIntChildValueCount() {
       }
     }
   }
+
+  @Test
+  public void testGetFieldBuffersOfEmptyVector() {
+    // An empty vector holds the allocator's shared empty buffer as its offsets until it allocates
+    try (LargeListVector vector = LargeListVector.empty("list", allocator)) {
+      vector.addOrGetVector(FieldType.nullable(MinorType.INT.getType()));
+      ArrowBuf offsets = vector.getFieldBuffers().get(1);
+      assertTrue(offsets.capacity() >= LargeListVector.OFFSET_WIDTH);
+      assertEquals(LargeListVector.OFFSET_WIDTH, offsets.readableBytes());
+      assertEquals(0L, offsets.getLong(0));
+      assertEquals(0, allocator.getEmpty().writerIndex());
+    }
+  }
 }

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

@@ -185,6 +185,21 @@ private ListVector emptyRowsOverNestedList() {
     return vector;
   }
 
+  /** Two empty rows over an inner list that still holds two large lists, [[1]] and [[2]]. */
+  private ListVector emptyRowsOverNestedLargeList() {
+    ListVector vector = ListVector.empty("l", allocator);
+    vector.addOrGetVector(FieldType.nullable(ArrowType.List.INSTANCE));
+    ListVector inner = (ListVector) vector.getDataVector();
+    inner.addOrGetVector(FieldType.nullable(ArrowType.LargeList.INSTANCE));
+    LargeListVector largeList = (LargeListVector) inner.getDataVector();
+    largeList.addOrGetVector(FieldType.nullable(MinorType.INT.getType()));
+    load(vector, 2, allValid(), ints(0, 0, 0));
+    load(inner, 2, allValid(), ints(0, 1, 2));
+    load(largeList, 2, allValid(), longs(0, 1, 2));
+    load(largeList.getDataVector(), 2, allValid(), ints(1, 2));
+    return vector;
+  }
+
   /**
    * One row over a dense union whose int child skips an element: union slots 0..3 hold child
    * elements 0, 1, 3 and 4, that is 10, 11, 13 and 14.
@@ -359,6 +374,21 @@ public void emptyCoveredRangeOverNestedListKeepsItsFirstOffset() {
     }
   }
 
+  @Test
+  public void emptyCoveredRangeOverNestedLargeListKeepsItsFirstOffset() {
+    try (ListVector vector = emptyRowsOverNestedLargeList();
+        VectorSchemaRoot root = VectorSchemaRoot.of(vector);
+        ArrowRecordBatch batch = new VectorUnloader(root).getRecordBatch();
+        VectorSchemaRoot loaded = reload(root, batch)) {
+      assertEquals(Arrays.asList(2, 0, 0, 0), lengths(batch));
+      assertEquals(Arrays.asList(1L, 12L, 0L, 4L, 0L, 8L, 0L, 0L), sizes(batch));
+      assertEquals(0L, batch.getBuffers().get(5).getLong(0));
+      ListVector read = (ListVector) loaded.getVector(0);
+      assertEquals(Collections.emptyList(), read.getObject(0));
+      assertEquals(Collections.emptyList(), read.getObject(1));
+    }
+  }
+
   @Test
   public void denseUnionChildIsWrittenUntrimmed() {
     try (ListVector vector = listOfDenseUnion(0, 3);