t/run/locale.t: uninitialized value warnings on OpenBSD

[jkeenan]

In the course of testing #23265 on OpenBSD-6.9, I observed previously unnoticed uninitialized value warnings.

Use of uninitialized value $locale in concatenation (.) or string at run/locale.t line 618.
Use of uninitialized value $locale in concatenation (.) or string at run/locale.t line 641.

See, e.g., https://perl.develop-help.com/dblog/5511983.

These warnings began to appear in my own OpenBSD smoke-test logs in early March. In all likelihood these warnings began to be emitted following this commit:

commit fecfa476ebefab8d99c628450d82a8b28a2fff42
Author:     Karl Williamson <[email protected]>
AuthorDate: Thu Jan 30 18:09:27 2025 -0700
Commit:     Karl Williamson <[email protected]>
CommitDate: Sun Feb 9 16:36:20 2025 -0700

    run/locale.t: Add test for UTF-8 string non-UTF8 locale
    
    This was suggested by Tony Cook at
    https://github.com/Perl/perl5/pull/22811#discussion_r1868633416

... as that commit contained 4 instances of:

+    my $locale = $non_utf8_locales[0];

... which were not checked for definedness before being used.

The branch in this pull request guarantees that $locale is initialized to an empty string if not otherwise defined. Please review.

[jkeenan]

@khwilliamson can you take a look at this p.r.? Thanks.

[khwilliamson]

It appears to me that the bug is more fundamental than this. Those entries should be defined; I would need to experiment on an OpenBSD system to figure it out.

[afresh1]

@khwilliamson : I can probably get you access to an OpenBSD machine if you need. I'm away this weekend, but we can figure something out next week.