RFR: 8324126: Error message for mistyping -XX:+Unlock...Options is not helpful [v3]

[David Holmes]

On Mon, 29 Jan 2024 21:05:46 GMT, Sonia Zaldana Calles <szaldana at openjdk.org> wrote:

>> If we run the VM option to unlock experimental vm options without the preceding ‘+’, the error message is not very helpful: 
>> 
>> ```Error: VM option 'UnlockExperimentalVMOptions' is experimental and must be enabled via -XX:+UnlockExperimentalVMOptions.```
>> 
>> With the proposed change, we should see a more descriptive error message, namely the lack of a +/- sign. 
>> 
>> ```Missing +/- setting for VM option 'UnlockExperimentalVMOptions'```
>> 
>> Testing: runtime/commandLine regression tests pass. Also added a regression test to verify expected behaviour.
>
> Sonia Zaldana Calles has updated the pull request incrementally with one additional commit since the last revision:
> 
>   restoring end of file

So now we will print the unlock message followed by any formatting error message? Can you provide sample output please. Thanks

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PR Comment: https://git.openjdk.org/jdk/pull/17575#issuecomment-1916160528