RFR: JDK-8292595: jdwp utf_util getWideString might leak memory [v2]

[Chris Plummer]

On Fri, 26 Aug 2022 12:04:57 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

>> There seems to be a case where utf_util.c getWideString might leak memory in an early return.
>
> Matthias Baesken has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Introduce UTF_WARNING and use the fallback

I'm not so sure I agree with enabling this "copy bytes" fallback code that has seemingly never been exercised. Until we find a use case where a `MultiByteToWideChar` failure is not deemed to be a fatal error, I think we should keep the code as is. Note these are possible reasons for `MultiByteToWideChar` failing:

    ERROR_INSUFFICIENT_BUFFER. A supplied buffer size was not large enough, or it was incorrectly set to NULL.
    ERROR_INVALID_FLAGS. The values supplied for flags were not valid.
    ERROR_INVALID_PARAMETER. Any of the parameter values was invalid.
    ERROR_NO_UNICODE_TRANSLATION. Invalid Unicode was found in a string.

Is there ever a reason we would not want to abort if one of these errors happened?

-------------

PR: https://git.openjdk.org/jdk/pull/9918