Code review request 7190219 CharBuffer position changed after BufferOverflowException in put()

[Alan Bateman]

On 09/08/2012 13:16, Jonathan Lu wrote:
> Hi folks,
>
> Here's a patch for bug 7190219, could you please help to have a look?
> http://cr.openjdk.java.net/~luchsh/7190219/
>
> According to the specification, in the method 
> java.nio.CharBuffer.put(String src, int start, int end).
> If there are more chars to be copied from the string than remain in 
> this buffer, that is, if end - start > remaining(), then no chars are 
> transferred and a|BufferOverflowException||| 
> <cid:part1.03040006.09080809 at linux.vnet.ibm.com> is thrown.
>
> But actually the test case from that webrev proves that the buffer was 
> modified even after BufferOverflowException, so I suggest to add 
> additional check after checkBounds() call, in the same way as 
> java.nio.CharBuffer.put(char[] src, int offset, int length).
You're right, it's missing a check to make sure that there is remaining 
space and the proposed change looks right to me. Just to keep things 
locally consistent you can remove the braces around the throw new 
BufferOverflowException.

I think the test could be improved. In particular it could duplicate the 
buffer and then check that it is equals to the duplicate after the put 
fails (in addition to checking that that the position hasn't changed). 
That way you really check that the buffer content haven't been modified. 
Do you mind seeing if you can add this to the existing unit test for the 
buffer classes rather than adding a new test? You'll see the existing 
tests in Basic.java and Basic-X.java.template.

I see you've submitted an incident via bugs.sun.com for this, I've moved 
to the right place as:

7190219: (bf) CharBuffer.put(String,int,int) modifies position even if 
BufferOverflowException thrown

-Alan.