Add test for RHBZ 481793 (passing, thanks to vg_read changes checked in

previously).

test/t-vgsplit-stacked.sh

@@ -0,0 +1,18 @@
+. ./test-utils.sh
+
+prepare_lvmconf '[ "a/dev\/mirror/", "a/dev\/mapper\/.*$/", "r/.*/" ]'
+aux prepare_devs 3
+
+pvcreate $devs
+vgcreate $vg1 $dev1 $dev2
+lvcreate -n $lv1 -l 100%FREE $vg1
+
+#top VG
+pvcreate $G_dev_/$vg1/$lv1
+vgcreate $vg $G_dev_/$vg1/$lv1 $dev3
+
+vgchange -a n $vg
+vgchange -a n $vg1
+
+# this should fail but not segfault, RHBZ 481793.
+not vgsplit $vg $vg1 $dev3

test/test-utils.sh

@@ -178,11 +178,14 @@ prepare_vg() {
 }
 
 prepare_lvmconf() {
+	local filter="$1"
+	test -z "$filter" && \
+		filter='[ "a/dev\/mirror/", "a/dev\/mapper\/.*pv[0-9_]*$/", "r/.*/" ]'
 	cat > $G_root_/etc/lvm.conf <<-EOF
   devices {
     dir = "$G_dev_"
     scan = "$G_dev_"
-    filter = [ "a/dev\/mirror/", "a/dev\/mapper\/.*pv[0-9_]*$/", "r/.*/" ]
+    filter = $filter
     cache_dir = "$G_root_/etc"
     sysfs_scan = 0
   }