[bugfix] Significant characters within a picture string for a Decimal Format must be distinct

Author: adamretter

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

@@ -556,6 +556,10 @@ throws PermissionDeniedException, EXistException, XPathException
                   }
 
                   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.");
+                  }
+
                   staticContext.setStaticDecimalFormat(qnDfName, df);
                   context.setStaticDecimalFormat(qnDfName, df);
             }

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

@@ -106,6 +106,36 @@ public DecimalFormat(final int decimalSeparator, final int exponentSeparator, fi
         this.minusSign = minusSign;
     }
 
+    /**
+     * Checks that the characters used in a picture string have distinct values.
+     *
+     * @return true if all the characters are distinct, false otherwise.
+     */
+    public boolean checkDistinctCharacters() {
+        final int[] characters = new int[] {
+            decimalSeparator,
+            exponentSeparator,
+            groupingSeparator,
+            percent,
+            perMille,
+            zeroDigit,
+            digit,
+            patternSeparator
+        };
+
+        for (int i = 0; i < characters.length; i++) {
+            final int c = characters[i];
+            for (int j = i + 1; j < characters.length; j++) {
+                final int o = characters[j];
+                if (c == o) {
+                    return false;
+                }
+            }
+        }
+
+        return true;
+    }
+
     public static DecimalFormat fromProperties(final Map<String, String> properties) {
         int decimalSeparator = UNNAMED.decimalSeparator;
         int exponentSeparator = UNNAMED.exponentSeparator;

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

@@ -220,6 +220,7 @@ public enum W3CErrorCode implements IErrorCode {
         XQDY0092 ("An implementation MAY raise a dynamic error  if a constructed attribute named xml:space has a value other than preserve or default."),
         XQST0093 ("It is a static error to import a module M1 if there exists a sequence of modules M1 ... Mi ... M1 such that each module directly depends on the next module in the sequence (informally, if M1 depends on itself through some chain of module dependencies.)"),
         XQST0094 ("The name of each grouping variable must be equal (by the eq operator on expanded QNames) to the name of a variable in the input tuple stream."),
+        XQST0098 ("It is a static error if, for any named or unnamed decimal format, the properties representing characters used in a picture string do not each have distinct values. The following properties represent characters used in a picture string: decimal-separator, exponent-separator, grouping-separator, percent, per-mille, the family of ten decimal digits starting with zero-digit, digit, and pattern-separator."),
         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."),