RFR: 8146793: logStream::write re-formats string

[Rachel Protacio]

Looks good to me, Kim! Thank you for fixing this. One note: I think you 
accidentally overwrote the original log.hpp copyright instead of adding 
to it.

Rachel

On 1/12/2016 10:25 AM, Kim Barrett wrote:
> Please review this fix to some problems in logStream::write and the
> facilities used to implement it.
>
> 1. logStream::write no longer attempt to reformat the already
> formatted accumulated output.  [Fixing this led to the discovery of
> the issues below.]
>
> 2. Fixed Log<>::vwrite test for overflow of the initial buffer, which
> didn't allow for the trailing NUL.
>
> 3. Fixed Log<>::vwrite to copy the va_list arguments before first
> format attempt and use that copy if a second format attempt is
> needed, rather than incorrectly reusing the original (now possibly
> modified) va_list.
>
> CR:
> https://bugs.openjdk.java.net/browse/JDK-8146793
>
> Webrev:
> http://cr.openjdk.java.net/~kbarrett/8146793/webrev.00/
>
> Testing:
> JPRT
> Locally verified printing a "%" to a log stream works, by running
> TestPrintGCDetailsVerbose (after fixing it for JDK-8146728).
>