[bugfix] #4958 return false() from empty nodeSetCompare

Author: Robin6939

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

@@ -648,6 +648,9 @@ 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 +1,38 @@
+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))]
+    )
+};