[bugfix] Empty In-memory NodeSet should have zero size

Author: adamretter

exist-core/pom.xml

@@ -1442,6 +1442,7 @@
                                 <include>src/main/java/org/exist/xquery/value/GYearMonthValue.java</include>
                                 <include>src/main/java/org/exist/xquery/value/GYearValue.java</include>
                                 <include>src/main/java/org/exist/xquery/value/IntegerValue.java</include>
+                                <include>src/main/java/org/exist/xquery/value/MemoryNodeSet.java</include>
                                 <include>src/main/java/org/exist/xquery/value/QNameValue.java</include>
                                 <include>src/main/java/org/exist/xquery/value/SequenceType.java</include>
                                 <include>src/main/java/org/exist/xquery/value/StringValue.java</include>
@@ -2271,6 +2272,7 @@
                                 <exclude>src/main/java/org/exist/xquery/value/GYearValue.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/value/IntegerValue.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/value/ItemComparator.java</exclude>
+                                <exclude>src/main/java/org/exist/xquery/value/MemoryNodeSet.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/value/QNameValue.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/value/SequenceComparator.java</exclude>
                                 <exclude>src/main/java/org/exist/xquery/value/SequenceType.java</exclude>

exist-core/src/main/java/org/exist/xquery/value/MemoryNodeSet.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * admin@evolvedbinary.com
+ * https://www.evolvedbinary.com | https://www.elemental.xyz
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; version 2.1.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * NOTE: Parts of this file contain code from 'The eXist-db Authors'.
+ *       The original license header is included below.
+ *
+ * =====================================================================
+ *
  * eXist-db Open Source Native XML Database
  * Copyright (C) 2001 The eXist-db Authors
  *
@@ -28,7 +52,7 @@
 
 public interface MemoryNodeSet extends Sequence {
 
-    MemoryNodeSet EMPTY = new ValueSequence(1);
+    MemoryNodeSet EMPTY = new ValueSequence(0);
 
     Sequence getAttributes(NodeTest test) throws XPathException;