Handle z/OS Unix ‘set’ output

Problem and fix reported by Jeff Shimoda in:
https://lists.gnu.org/r/autoconf-patches/2022-06/msg00007.html
* tests/local.at (AT_CONFIG_CMP): Treat ‘var=""’ like ‘var=''’.
Copyright-paperwork-exempt: Yes

diff --git a/tests/local.at b/tests/local.at
index f79f57ff1569291ed2ab755b59a49718df264631..193fd11858725f649b1c2e627a7fb44dcf7d85ed 100644 (file)
--- a/tests/local.at
+++ b/tests/local.at
@@ -476,6 +476,7 @@ do
   $SED '/^ac_cv_/ b skip
        /^m4_defn([m4_re_word])=./ !d
        /^[[^=]]*='\'''\''$/ d
+       /^[[^=]]*=""$/ d
        /^a[[cs]]_/ d
        : skip
        /^OLDPWD=/ d