standards/60254: POSIX.1-2024: PTHREAD_NULL

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>Number:         60254
>Category:       standards
>Synopsis:       POSIX.1-2024: PTHREAD_NULL
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    standards-manager
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue May 12 20:50:00 +0000 2026
>Originator:     Taylor R Campbell
>Release:        current, 11, 10, 9, ...
>Organization:
The Nullpthread_t Foundation
>Environment:
>Description:
> The <pthread.h> header shall define the following compile-time
> constant expression, valid as an initializer for pthread_t,
> representing a value that shall not compare equal to the thread ID of
> any existing thread:
> 
> PTHREAD_NULL

https://pubs.opengroup.org/onlinepubs/9799919799.2024edition/basedefs/pthread.h.html
>How-To-Repeat:
standards inspection and/or chasing silly OpenSSL bugs
>Fix:
Yes, please!

Note that pthread_equal needs to be taught to stomach this value.