[bugfix] 4810-Fixed comparison and predicate execution

Author: Robin6939

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

@@ -377,7 +377,11 @@ private Sequence selectByNodeSet(final Sequence contextSequence) throws XPathExc
         final NodeSet contextSet = contextSequence.toNodeSet();
         final boolean contextIsVirtual = contextSet instanceof VirtualNodeSet;
         contextSet.setTrackMatches(false);
-        final NodeSet nodes = super.eval(contextSet, null).toNodeSet();
+        final Sequence x = super.eval(contextSet, null);
+        if(!(x instanceof NodeSet))
+            return x;
+        final NodeSet nodes = result.toNodeSet();
+
         /*
          * if the predicate expression returns results from the cache we can
          * also return the cached result.

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

@@ -0,0 +1,32 @@
+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 {
+    <Y1 id="1">
+        <H1 id="2" a2="2">true</H1>
+    </Y1>
+};
+
+declare
+    %test:setUp
+function t:setup() {
+    let $testCol := xmldb:create-collection("/db", "test")
+    return
+        xmldb:store("/db/test", "test.xml", $t:XML)
+};
+
+declare
+    %test:tearDown
+function t:tearDown() {
+    xmldb:remove("/db/test")
+};
+
+declare
+    %test:assertTrue
+function t:test() {
+    doc("/db/test/test.xml")//*[starts-with(@a2, "1") = false()]
+    => exists()
+};