[bugfix] Query prolog must not allow two decimal format declarations with the same name

Author: adamretter

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

@@ -106,6 +106,7 @@ options {
     protected Set<String> importedModules = new HashSet<>();
     protected Set<String> importedModuleFunctions = null;
     protected Set<QName> importedModuleVariables = null;
+    private boolean hasDefaultDecimalFormat = false;
 
     public XQueryTreeParser(XQueryContext context) {
         this(context, null);
@@ -504,6 +505,26 @@ throws PermissionDeniedException, EXistException, XPathException
                   // first sibling is either DEFAULT_DECIMAL_FORMAT (default) or EQNAME (named)
                   final XQueryAST dfName = (XQueryAST) root.getNextSibling();
 
+                  final QName qnDfName;
+                  if ("default".equals(dfName.getText())) {
+                      qnDfName = XQueryContext.UNNAMED_DECIMAL_FORMAT;
+                      if (hasDefaultDecimalFormat) {
+                          throw new XPathException(dfName.getLine(), dfName.getColumn(), ErrorCodes.W3CErrorCode.XQST0111.getErrorCode(), "Query prolog cannot contain two default decimal format declarations.");
+                      } else {
+                          hasDefaultDecimalFormat = true;
+                      }
+                  } else {
+                      try {
+                          qnDfName = QName.parse(staticContext, dfName.getText(), null);
+                      } catch (final IllegalQNameException iqe) {
+                          throw new XPathException(dfName.getLine(), dfName.getColumn(), ErrorCodes.XPST0081, "No namespace defined for prefix " + dfName.getText());
+                      }
+
+                      if (staticContext.getStaticDecimalFormat(qnDfName) != null) {
+                          throw new XPathException(dfName.getLine(), dfName.getColumn(), ErrorCodes.W3CErrorCode.XQST0111.getErrorCode(), "Query prolog cannot contain two decimal format declarations with the same name: " + dfName.getText());
+                      }
+                  }
+
                   // position current at the first property name for the decimal format
                   XQueryAST current = (XQueryAST) dfName.getNextSibling();
                   if ("default".equals(dfName.getText())) {
@@ -530,17 +551,6 @@ throws PermissionDeniedException, EXistException, XPathException
                       current = (XQueryAST) pval.getNextSibling();
                   }
 
-                  final QName qnDfName;
-                  if ("default".equals(dfName.getText())) {
-                      qnDfName = XQueryContext.UNNAMED_DECIMAL_FORMAT;
-                  } else {
-                      try {
-                          qnDfName = QName.parse(staticContext, dfName.getText(), null);
-                      } catch (final IllegalQNameException iqe) {
-                          throw new XPathException(dfName.getLine(), dfName.getColumn(), ErrorCodes.XPST0081, "No namespace defined for prefix " + dfName.getText());
-                      }
-                  }
-
                   final DecimalFormat df = DecimalFormat.fromProperties(dfProperties);
                   if (!df.checkDistinctCharacters()) {
                       throw new XPathException(dfName.getLine(), dfName.getColumn(), ErrorCodes.W3CErrorCode.XQST0098.getErrorCode(), "Characters within the picture string of the decimal format: " + dfName.getText() + " are not distinct.");

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

@@ -224,6 +224,7 @@ public enum W3CErrorCode implements IErrorCode {
         XQDY0101 ("An error is raised if a computed namespace constructor attempts to do any of the following: Bind the prefix xml to some namespace URI other than http://www.w3.org/XML/1998/namespace. Bind a prefix other than xml to the namespace URI http://www.w3.org/XML/1998/namespace. Bind the prefix xmlns to any namespace URI. Bind a prefix to the namespace URI http://www.w3.org/2000/xmlns/. Bind any prefix (including the empty prefix) to a zero-length namespace URI."),
         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."),
         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."),