[bugfix] empty array constructor thorws error

Author: marmoure

exist-core/src/main/java/org/exist/xquery/functions/array/ArrayConstructor.java

@@ -74,7 +74,7 @@ public Sequence eval(Sequence contextSequence, Item contextItem) throws XPathExc
                 }
                 return new ArrayType(this, context, items);
             default:
-                final Sequence result = arguments.get(0).eval(contextSequence, contextItem);
+                final Sequence result =  arguments.isEmpty() ? Sequence.EMPTY_SEQUENCE : arguments.get(0).eval(contextSequence, contextItem);
                 return new ArrayType(this, context, result);
         }
     }

exist-core/src/test/xquery/arrays/arrays.xql

@@ -235,6 +235,13 @@ function arr:curly-constructor2($pos as xs:int) {
     return $a($pos)
 };
 
+declare
+    %test:assertEmpty
+function arr:curly-constructor3() {
+    let $a := array {}
+    return $a?*
+};
+
 declare
     %test:assertTrue
 function arr:deep-equal1() {