On Tue, 6 Dec 2022 15:28:24 GMT, Sergey Tsypanov <stsypa...@openjdk.org> wrote:
>> I found out that this code
>>
>> public class Main {
>> public static void main(String[] args) {
>> String s = "Hello world!";
>> char[] chars = s.toCharArray();
>> int point = Character.codePointAt(chars, -1, 1);
>> }
>> }
>>
>> throws `ArrayIndexOutOfBoundsException` instead of JavaDoc-specified
>> `IndexOutOfBoundsException`:
>>
>> Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: Index
>> -1 out of bounds for length 12
>> at java.base/java.lang.Character.codePointAtImpl(Character.java:9254)
>> at java.base/java.lang.Character.codePointAt(Character.java:9249)
>> at org.example.Main.main(Main.java:7)
>>
>> and the method doesn't check whether `index` parameter is negative:
>>
>> public static int codePointAt(char[] a, int index, int limit) {
>> if (index >= limit || limit < 0 || limit > a.length) {
>> throw new IndexOutOfBoundsException();
>> }
>> return codePointAtImpl(a, index, limit);
>> }
>>
>> I suggest to check the `index` parameter explicitly instead of relying on
>> AIOOBE thrown from accessing the array with negative index.
>
> Sergey Tsypanov has updated the pull request incrementally with one
> additional commit since the last revision:
>
> 8298033: Fix Character.codePointBefore()
src/java.base/share/classes/java/lang/Character.java line 9480:
> 9478: */
> 9479: public static int codePointBefore(char[] a, int index, int start) {
> 9480: if (index <= start || start < 0 || start >= a.length || index >
> a.length) {
Since `index > start` it is sufficient to throw `index > a.length`.
The check `start >= a.length` is redundant.
`0 <= start < index <= a.length`
-------------
PR: https://git.openjdk.org/jdk/pull/11480
