[bugfix] Return alse instead of () in GeneralComparison when no operands match (#4958)

Author: Robin6939

exist-core/pom.xml

@@ -766,6 +766,7 @@
                                 <include>src/test/java/org/exist/xquery/functions/xmldb/XMLDBStoreTest.java</include>
                                 <include>src/test/java/org/exist/xquery/functions/xquery3/SerializeTest.java</include>
                                 <include>src/test/java/org/exist/xquery/value/DateTimeTypesTest.java</include>
+                                <include>src/test/xquery/emptySeq.xq</include>
                             </includes>
                         </licenseSet>
 
@@ -1085,6 +1086,7 @@
                                 <include>src/main/java/org/exist/xslt/EXistURIResolver.java</include>
                                 <include>src/main/java/org/exist/xslt/XsltURIResolverHelper.java</include>
                                 <include>src/test/java/org/exist/xupdate/RemoveAppendTest.java</include>
+                                <include>src/main/java/org/exist/xquery/GeneralComparison.java</include>
                             </includes>
                         </licenseSet>
 
@@ -1538,7 +1540,8 @@
                                 <exclude>src/main/java/org/exist/xslt/EXistURIResolver.java</exclude>
                                 <exclude>src/main/java/org/exist/xslt/XsltURIResolverHelper.java</exclude>
                                 <exclude>src/test/java/org/exist/xupdate/RemoveAppendTest.java</exclude>
-
+                                <exclude>src/main/java/org/exist/xquery/GeneralComparison.java</exclude>
+                                <exclude>src/test/xquery/emptySeq.xq</exclude>
                                 <!--
                                     Derivative work licensed under dbXML 1.0 and LGPL 2.1
                                 -->

exist-core/src/main/java/org/exist/xquery/GeneralComparison.java

@@ -1,4 +1,28 @@
 /*
+ * Elemental
+ * Copyright (C) 2024, Evolved Binary Ltd
+ *
+ * [email protected]
+ * 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
  *
@@ -648,6 +672,9 @@ protected Sequence nodeSetCompare( NodeSet nodes, Sequence contextSequence ) thr
                     }
                 }
             }
+            if (result.isEmpty()) {
+                return BooleanValue.FALSE;
+            }
         }
 
         if( context.getProfiler().traceFunctions() ) {

exist-core/src/test/xquery/emptySeq.xq

@@ -0,0 +1,58 @@
+(:
+ : Elemental
+ : Copyright (C) 2024, Evolved Binary Ltd
+ :
+ : [email protected]
+ : 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
+ :)
+xquery version "3.1";
+
+module namespace t="http://exist-db.org/xquery/test";
+
+declare namespace test="http://exist-db.org/xquery/xqsuite";
+
+declare variable $t:XML := document {
+    <F id="1"/>
+};
+
+declare
+    %test:setUp
+function t:setup() {
+    xmldb:create-collection("/db", "test"),
+    xmldb:store("/db/test", "test.xml", $t:XML)
+};
+
+declare
+    %test:tearDown
+function t:tearDown() {
+    xmldb:remove("/db/test")
+};
+
+declare
+    %test:assertTrue
+function t:test-db() {
+    exists(
+        doc("/db/test/test.xml")//F[boolean(count(@id >= 2))]
+    )
+};
+
+declare
+    %test:assertTrue
+function t:test-mem() {
+    exists(
+        $t:XML//F[boolean(count(@id >= 2))]
+    )
+};