illumos gate

Hi.

I found a strange problem with metaflac which cannot read (and write) tags anymore.
Just try metaflac --list <some flac audio file>.
Even my own compiled executables show this error.
I boiled the problem down to a little test program, see attachment.

With truss you can see that before the read there is an ioctl which sets errno to ENOTTY.
The read just thereafter succeeds but does not reset errno.
I have an older system which does not behave that way and seems to reset errno to zero:

what /lib/64/libc.so.1
   /lib/64/libc.so.1:
            illumos illumos-cf56021bf3 October 2022

The actual OpenIndiana does show this problem:

what /lib/64/libc.so.1

/lib/64/libc.so.1:
            illumos illumos-f137b22e73 December 2022

Note that strictly speaking the code of the program and of metaflac is not correct
since they should not look at the errno if the read call gets data.
There are also some Linux discussions how libc should behave concerning errno
and changes of the standards in libc.

Best regards,
Thomas.