Portable mktemp calls in the tests

[Martin Schwenke]

Hi Timur,

On Fri, 22 Dec 2017 02:49:48 +0100, "Timur I. Bakeyev via
samba-technical" <samba-technical at lists.samba.org> wrote:

> Here is another piece of puzzle of making samba autobuild work out of the
> box on FreeBSD.
> 
> There are plenty of places in the tests where 'mktemp` is called with
> '--tempdir' or '-p' parameter, which are not recognized on FreeBSD(and,
> possibly other Unix-like platforms).
> 
> This call can be safely replaced with the sequence:
> 
> $(TMPDIR="$TEST_VAR_DIR" mktemp -d)

First the long-winded rant about poor documentation...  :-)

I have a *minor* concern because neither the Linux nor FreeBSD manpages
for mktemp(1) clearly document the general use of TMPDIR.  Use of TMPDIR
is documented in the context of the -t option (and, for Linux, the -p
option).

The FreeBSD manpage and Linux info page each have an example that I
would regard as implying general use of TMPDIR to override the use
of /tmp.

That said, it clearly works on most Unix-related platforms.  Testing
under Linux shows that mktemp uses TMPDIR in general cases and a glance
at the source code confirms this.

Given that I don't know how to write texinfo documentation, I've opened
a bug (https://debbugs.gnu.org/cgi/bugreport.cgi?bug=29807) against the
GNU coreutils package to try to get this documented.  I would encourage
you to do the same for FreeBSD's mktemp.

All that said, even though the documentation of mktemp is poor, I think
this is an improvement and would be happy to give it a positive
review.

However, can you please remove the following change (and those related
to it) from the mktemp commit?

-cat >$tmpeditor <<-'EOF'
+cat >${tmpeditor}.sh <<-'EOF'

If you really meant to do that then can you please make that change
in a separate commit?  :-)

Thanks...

peace & happiness,
martin