Re: [PATCH] t0005: ksh93 portability workaround

On Tue, May 31, 2016 at 03:47:01PM -0700, Junio C Hamano wrote:

The test has two things ksh93 does not happy about:

 * It thinks "(( command1; command2 ) | command3)" is a perfectly
   sane way to write a pipeline.  ksh93, unlike other POSIX shells,
   does not like the two open parentheses next to each other for
   whatever reason it has.

 * It adds 256, unlike 128 that are used by other POSIX shells, to
   the signal number that caused the process to die when coming up
   with the exit status.

What is interesting is that we knew about the latter issue and had a
workaround in the test-sigchain test when verifying that SIGTERM
works OK, but we didn't have corresponding workaround for SIGPIPE.

Hmm. We discussed these back in:

  http://thread.gmane.org/gmane.comp.version-control.git/268657

but I thought we decided not to do anything about them (according to
that thread, I found a bunch of other ksh93 oddities, but maybe we've
since fixed them?).

+died_with_sigpipe () {
+	case "$1" in
+	141 | 269)
+		# POSIX w/ SIGPIPE=13 gives 141
+		# ksh w/ SIGPIPE=13 gives 269
+		true ;;
+	*)	false ;;
+	esac
+}

This is OK, but I like the patch I posted in

  http://article.gmane.org/gmane.comp.version-control.git/268666

better, as it contains the shell logic in a single place (though I am
not sure how these tests fare on Windows, where I think every signal
just looks like "3").

-Peff