[bugfix] Correct the null checks in equality of MatchTerm

Author: adamretter

exist-core/src/main/java/org/exist/dom/persistent/Match.java

@@ -397,9 +397,8 @@ public boolean equals(final Object other) {
 
         if (other instanceof Match) {
             final Match om = (Match) other;
-            return om.matchTerm != null
-                    && om.matchTerm.equals(matchTerm)
-                    && om.nodeId.equals(nodeId);
+            return om.nodeId.equals(nodeId)
+		    && ((om.matchTerm != null && om.matchTerm.equals(matchTerm)) || matchTerm == null);
         } else {
             return false;
         }