tests: Add regression test for malformed sets

see: 5afa5a164ff1c066af1ec56d875b91562882bd50
When a malformed set is added, it was added before erroring out, causing a
segfault further down when used. This tests for this case, ensuring that
nftables doesn't segfault but errors correctly

Signed-off-by: Anatole Denis <anatole@rezel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/tests/shell/testcases/sets/0014malformed_set_is_not_defined_0 b/tests/shell/testcases/sets/0014malformed_set_is_not_defined_0
new file mode 100755 (executable)
index 0000000..5d1a2da
--- /dev/null
+++ b/tests/shell/testcases/sets/0014malformed_set_is_not_defined_0
@@ -0,0 +1,33 @@
+#!/bin/bash
+
+# This tests for the bug corrected in commit 5afa5a164ff1c066af1ec56d875b91562882bd50.
+# Sets were added to the table before checking for errors, and not removed from
+# the table on error, leading to an uninitialized set in the table, causing a
+# segfault for rules that tried to use it.
+# In this case, nft should error out because the set doesn't exist instead of
+# segfaulting
+
+tmpfile=$(mktemp)
+if [ ! -w $tmpfile ] ; then
+       echo "Failed to create tmp file" >&2
+       exit 0
+fi
+
+trap "rm -rf $tmpfile" EXIT # cleanup if aborted
+
+echo "
+add table t
+add chain t c
+add set t s {type ipv4_addr\;}
+add rule t c ip saddr @s
+" >$tmpfile
+
+$NFT -f $tmpfile
+ret=$?
+
+trap - EXIT
+if [[ $ret -eq 1 ]]; then
+       exit 0
+else
+       exit 1
+fi