[bugfix] A decimal format must only define the same property once

Author: adamretter

exist-core/src/main/antlr/org/exist/xquery/parser/XQueryTree.g

@@ -560,7 +560,9 @@ throws PermissionDeniedException, EXistException, XPathException
                       if (pv.length() >= 2 && (pv.startsWith("\"") || pv.startsWith("'"))) {
                           pv = pv.substring(1, pv.length() - 1);
                       }
-                      dfProperties.put(pn, pv);
+                      if (dfProperties.put(pn, pv) != null) {
+                          throw new XPathException(dfName.getLine(), dfName.getColumn(), ErrorCodes.W3CErrorCode.XQST0114.getErrorCode(), "Decimal format: " + dfName.getText() + " defines the property: " + pn + " more than once.");
+                      }
 
                       current = (XQueryAST) pval.getNextSibling();
                   }

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

@@ -225,6 +225,7 @@ public enum W3CErrorCode implements IErrorCode {
         XQDY0102 ("If the name of an element in an element constructor is in no namespace, creating a default namespace for that element using a computed namespace constructor is an error."),
         XQST0103 ("All variables in a window clause must have distinct names."),
         XQST0111 ("It is a static error for a query prolog to contain two decimal formats with the same name, or to contain two default decimal formats."),
+        XQST0114 ("It is a static error for a decimal format declaration to define the same property more than once."),
         XQDY0137 ("No two keys in a map may have the same key value"),
         XQDY0138 ("Position n does not exist in this array"),
         XUDY0023 ("It is a dynamic error if an insert, replace, or rename expression affects an element node by introducing a new namespace binding that conflicts with one of its existing namespace bindings."),