DevHeads.net

Fix check for file descriptor passing

On a musl-based system, postfix incorrectly assumes that file descriptor
passing is not available, because of this line in sys_defs.h:

It builds fine, but when used with a milter or the postscreen daemon, it
will fail at runtime with this error:

See also [1] and [2].

[1] - <a href="https://github.com/gentoo/musl/issues/53" title="https://github.com/gentoo/musl/issues/53">https://github.com/gentoo/musl/issues/53</a>
[2] - <a href="https://bugs.alpinelinux.org/issues/3423" title="https://bugs.alpinelinux.org/issues/3423">https://bugs.alpinelinux.org/issues/3423</a>

Find attached a patch that will fix this issue.