String.lastIndexOf confused by unpaired trailing surrogate

[Xueming Shen]

CCed Masayoshi.

Masayoshi, Martin and Ulf are doing some "small" overhaul on those 
supplementary methods guess
you might be interested to review the change.

Martin, Ulf, please CC Masayoshi if you are touching the supplementary 
handling code.

-Sherman

Xueming Shen wrote:
> 6937112: String.lastIndexOf confused by unpaired trailing surrogate
>
> Kinda guess that it might bring us some performance benefit to 
> separate the supplementary handling
> code out into its own method (to help the not that smart hotspot:-)?), 
> but doubt it is really something
> worth doing. At  least you dont have to have the redundant 
> value/offset=this.value/offset.
>
> Seems like you started to attach the "final" keyword to all 
> "constants"...guess it's a hint to help smart
> vm for further optimization. Is the hotspot doing something special in 
> simple case like below?
>
> -Sherman
>
> Martin Buchholz wrote:
>> For a change, here's an actual plain old "incorrect result" bug fix
>> for String.lastIndexOf
>>
>> Sherman, please file a bug and review.
>>
>> http://cr.openjdk.java.net/~martin/webrevs/openjdk7/lastIndexOf/
>>
>> Also includes our usual performance-oriented fiddling.
>>
>> public class LastIndexOf {
>>     public static void main(String[] args) {
>>         int ch = 0x10042;
>>         char[] bug = new char[3];
>>         Character.toChars(ch, bug, 0);
>>         bug[2] = bug[0];
>>         System.out.println(new String(bug).lastIndexOf(ch));
>>         bug[2] = '!';
>>         System.out.println(new String(bug).lastIndexOf(ch));
>>     }
>> }
>> ==> javac -source 1.6 -Xlint:all LastIndexOf.java
>> ==> java -esa -ea LastIndexOf
>> -1
>> 0
>>   
>
>