RFR: 8343618: Stack smashing in awt_InputMethod.c on Linux s390x

[Ichiroh Takiguchi]

On Wed, 23 Apr 2025 15:10:29 GMT, Zdenek Zambersky <zzambers at openjdk.org> wrote:

>> Attaching jdk_awt jtreg results (with and without fix).
>> [jdk-awt-results.tgz](https://github.com/user-attachments/files/19430946/jdk-awt-results.tgz)
>
>> @zzambers Sorry for my late reaction. Is it possible to add test result by using `XMODIFIERS=@im=local` ?
> 
> Thank you for you reaction.
> 
> I can do some additional testing. You mean to just run the tests with `XMODIFIERS` env. variable set to given value? Are there any other requirements about test system? Note that I only have access to headless linux/s390x machines, so I used Xvfb as X11 server.

@zzambers 
Sorry I'm late.
I could recreate your issue.
In my investigation,
Case 1: When I specified usable IM name, like `XMODIFIERS=@im=kinput2`, ` XGetICValues` returns like `0x200000000` instead of `0x2`.
Case 2: When I specified `XMODIFIERS=@im=local`, ` XGetICValues` returns `0x2`.
(It's the same as `XMODIFIERS=@im=none` or XMODIFIERS is unset)
I think it means case 2 just handles inside of Xlib without X protocol.
Your fix works fine on my test environment.

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PR Comment: https://git.openjdk.org/jdk/pull/24197#issuecomment-2863698338