Sun "sed" doesn't do substitute and print correctly

[Scott Guthridge]

System:
	Sun 3/280S-8, model 180
	software release: 4.0

Reported by:
	Scott Guthridge
	Purdue University Computing Center
	Mathematical Sciences Building
	West Lafayette, IN  47907
	(317) 494-1787
	aho at mentor.cc.purdue.edu

Problem description:
	The substitute command in sed takes an optional flag, "p", that
	should print the pattern space if a substitution was just made.

	On our suns and ETA, the following program doesn't produce any
	output.  It works fine under 4.3BSD, Ultrix 2.0, and Dynix 3.0.
	It fails under Sunos 4.0 and under ETA System V.

Test Program:

	Remove the indent from the following and run it with sh.

	#!/bin/sh
	#
	# This script should print the word "dog".
	#
	cat > try.sed$$ << \HERE
	s/cat/dog/p
	d
	HERE

	sed -f try.sed$$ << \HERE
	abc
	cat
	def
	HERE

	rm try.sed$$

Additional Information:

	If you give sed the "-n" command line option, the problem seems to
	go away; this isn't an acceptable work around in all cases.