🚀 go-pugleaf

	The Makefiles in ./dom and ./chn in the UK Sendmail-1.5 distribution
	fall over in certain circumstances under make on Ultrix.
	Rules of the form:
		-@if [ some test ]; then statement; fi
	emit error code 1 (which is ignored by make) if sometest is false.
	Without the "-", the error causes make to fail.
	The second test in the Makefiles (for host.{chn,dom} being non-empty)
	didn't have the "-" and so stopped the make.  A solution is to put a "-"
	at the front of the command:
		-@if [ ! -s $@ ] ; \
But the intention *is* to stop the make if the generated file is null ...
are you saying the make stops when the file is non-null ? That is, when
the test fails ? This is really nasty ! 
To abort  when the file is null, we need to invert the test.

	Another improvement is to put a dummy "else" part into these if commands.
	This stops the "Error code 1 (ignored)" message if `some test' is false.

Good idea.	

I suggest the following fragment.

        @if [ -s $@ ] ; \
                then :; \
                else    echo "$@ null - Abort" ;\
                        if [ -s $@.BCK ] ; then mv $@.BCK $@ ; fi;\
                        exit 99 ; fi