bug#23768: [PATCH] tests: adjust to ignore gzip 1.8+ warnings

[Ludovic Courtès]

This fixes a test failure when testing with gzip 1.8.

* t/distcheck-no-prefix-or-srcdir-override.sh: Instead of testing for an
empty 'stderr' file, check for a zero-line file once gzip warnings have
been removed.
---
 t/distcheck-no-prefix-or-srcdir-override.sh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/t/distcheck-no-prefix-or-srcdir-override.sh 
b/t/distcheck-no-prefix-or-srcdir-override.sh
index bef334b..f9d05e1 100644
--- a/t/distcheck-no-prefix-or-srcdir-override.sh
+++ b/t/distcheck-no-prefix-or-srcdir-override.sh
@@ -49,7 +49,11 @@ grep "cannot find sources.* in foobar" stderr || exit 99
 
 ./configure
 run_make -E -O distcheck
-test ! -s stderr
+
+# Gzip 1.8+ emits warnings like "gzip: warning: GZIP environment
+# variable is deprecated"; filter them out.
+test `grep -v '^gzip: warning' stderr | wc -l` -eq 0
+
 # Sanity check: the flags have been actually seen.
 $PERL -e 'undef $/; $_ = <>; s/ \\\n/ /g; print;' <stdout >t
 grep '/configure .* --srcdir am-src'   t || exit 99
-- 
2.8.3