Re: [PATCH] p3400: stop using tac(1)

From: Jeff King <peff@peff.net>
Date: Oct 4, 2021, 08:31 UTC
Message-ID: <YVq752xjzYz+LTq6@coredump.intra.peff.net>
In-Reply-To: <85831cc2-307f-1be8-9bb3-c44028ad07fa@web.de>

On Sat, Oct 02, 2021 at 07:44:14PM +0200, René Scharfe wrote:

> b3dfeebb92 (rebase: avoid computing unnecessary patch IDs, 2016-07-29)
> added a perf test that calls tac(1) from GNU core utilities.  Support
> systems without it by reversing the generated list using sort -nr
> instead.  sort(1) with options -n and -r is already used in other tests.

Cute fix. With regular seq(1), this whole thing can become:

  seq 1000 -1 1

without the extra process, but our test_seq doesn't understand non-1 increments (nor comparisons besides -le). It wouldn't be that hard to teach it, but given that this is the first time we've wanted it, it may not be worth the effort.

-Peff

diff --git a/t/test-lib-functions.sh b/t/test-lib-functions.sh
index 6348e8d733..76c8c0f2f6 100644
--- a/t/test-lib-functions.sh
+++ b/t/test-lib-functions.sh
@@ -1149,15 +1149,22 @@ test_cmp_fspath () {
 
 test_seq () {
 	case $# in
-	1)	set 1 "$@" ;;
-	2)	;;
-	*)	BUG "not 1 or 2 parameters to test_seq" ;;
+	1)	set 1 1 "$1" ;;
+	2)	set "$1" 1 "$2" ;;
+	3)	;;
+	*)	BUG "not 1, 2, or 3 parameters to test_seq" ;;
 	esac
+	if test "$1" -lt "$3"
+	then
+		test_seq_cmp__=-le
+	else
+		test_seq_cmp__=-ge
+	fi
 	test_seq_counter__=$1
-	while test "$test_seq_counter__" -le "$2"
+	while test "$test_seq_counter__" $test_seq_cmp__ "$3"
 	do
 		echo "$test_seq_counter__"
-		test_seq_counter__=$(( $test_seq_counter__ + 1 ))
+		test_seq_counter__=$(( $test_seq_counter__ + $2 ))
 	done
 }