Set/use $as_unset, for those shells

(like Ultrix4's /bin/sh) that don't accept `unset'.

diff --git a/tests/envvar-check b/tests/envvar-check
index 5784949d2a30da1bd89fbec4567a1f458a591f29..880eaccfce64b7a165d5da525a7b345ac9ebbe29 100644 (file)
--- a/tests/envvar-check
+++ b/tests/envvar-check
@@ -1,4 +1,10 @@
-unset VERSION_CONTROL SIMPLE_BACKUP_SUFFIX
+if (FOO=FOO; unset FOO) >/dev/null 2>&1; then
+  as_unset=unset
+else
+  as_unset=false
+fi
+
+$as_unset VERSION_CONTROL SIMPLE_BACKUP_SUFFIX
 
 if test "${VERSION_CONTROL+set}" = set; then
   echo "$0: the VERSION_CONTROL envvar is set --" \