Summary

Correct the prefix and suffix portion of pattern syntax for Decimal / CompactNumber Format.

Problem

Both of the Format classes list the suffix and prefix as allowing: "any Unicode characters except U+FFFE, U+FFFF, and special characters".

However, U+FFFE and U+FFFF are both able to be included in the pattern syntax with no exception thrown.

E.g. (For clarification, in the example, the U+FFFE and U+FFFF characters are replaced by U+FFFD / replacement character)

String uFFFE = "\uFFFE";
String uFFFF = "\uFFFF";
var a = new DecimalFormat("prefixStart"+uFFFE+"0.00"+uFFFF+"SuffixEnd");
a.format(1); // returns "prefixStart�1.00�SuffixEnd"

Solution

Remove U+FFFE and U+FFFF from both the prefix and suffix definition. Also remove 'Unicode', as a Java character is composed of Unicode codepoints.

Specification

CompactNumberFormat.java

  * <i>Prefix:</i>
- *      Any Unicode characters except {@code U+FFFE}, {@code U+FFFF}, and
- *      {@linkplain DecimalFormat##special_pattern_character special characters}.
+ *      Any characters except the {@linkplain
+ *      DecimalFormat##special_pattern_character special pattern characters}
  * <i>Suffix:</i>
- *      Any Unicode characters except {@code U+FFFE}, {@code U+FFFF}, and
- *      {@linkplain DecimalFormat##special_pattern_character special characters}.
+ *      Any characters except the {@linkplain
+ *      DecimalFormat##special_pattern_character special pattern characters}

DecimalFormat.java

  * <i>Prefix:</i>
- *         any Unicode characters except {@code U+FFFE}, {@code U+FFFF}, and special characters
+ *         Any characters except the {@linkplain ##special_pattern_character
+ *         special pattern characters}
  * <i>Suffix:</i>
- *         any Unicode characters except {@code U+FFFE}, {@code U+FFFF}, and special characters
+ *         Any characters except the {@linkplain ##special_pattern_character
+ *         special pattern characters}
  * <i>Number:</i>
  *         <i>Integer</i> <i>Exponent<sub>opt</sub></i>
  *         <i>Integer</i> . <i>Fraction</i> <i>Exponent<sub>opt</sub></i>