[bugfix] Fix an ArrayOutOfBoundException with array:get

Closes #2317

Author: adamretter

src/org/exist/xquery/functions/array/ArrayFunction.java

@@ -249,7 +249,7 @@ public Sequence eval(Sequence[] args, Sequence contextSequence) throws XPathExce
                         return new IntegerValue(array.getSize());
                     case GET:
                         final IntegerValue index = (IntegerValue) args[1].itemAt(0);
-                        return array.get(index.getInt() - 1);
+                        return array.get(index);
                     case APPEND:
                         return array.append(args[1]);
                     case HEAD:

test/src/xquery/arrays/arrays.xql

@@ -134,6 +134,14 @@ function arr:function-item-invalid() {
         $a("x")
 };
 
+declare
+    %test:assertError("FOAY0001")
+function arr:get-item-out-of-bounds() {
+    let $a := [13, 10, 14]
+    return
+        array:get($a, 22)
+};
+
 declare
     %test:args(1)
     %test:assertEmpty