tests: shell: check for table re-definition usecase

Make sure nft behaves like 0.9.0 -- the ruleset

flush ruleset
table inet filter {
}
table inet filter {
      chain test {
        counter
    }
}

loads again without crashing/generating an error message.

Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1351
Fixes: e5382c0d08e3c ("src: Support intra-transaction rule references")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/tests/shell/testcases/cache/0004_cache_update_0 b/tests/shell/testcases/cache/0004_cache_update_0
new file mode 100755 (executable)
index 0000000..697d9de
--- /dev/null
+++ b/tests/shell/testcases/cache/0004_cache_update_0
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+set -e
+
+# Trigger a crash or rule restore error with nft 0.9.1
+$NFT -f - >/dev/null <<EOF
+flush ruleset
+table inet testfilter {
+}
+table inet testfilter {
+      chain test {
+        counter
+    }
+}
+EOF