pasta: Regression test for bug 216HEADmaster

Adds a test that asserts that when pasta is invoked via `unshare -r` in
standalone mode with `--netns-only` it does not print any warnings, and
the command executes successfully.

Link: https://bugs.passt.top/show_bug.cgi?id=216
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Dwayne B. Bent <dbb@dbb.dev>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

2 files changed, 20 insertions, 0 deletions

diff --git a/test/pasta_options/netns_only b/test/pasta_options/netns_only
new file mode 100644
index 0000000..197ed44
--- /dev/null
+++ b/test/pasta_options/netns_only
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# PASST - Plug A Simple Socket Transport
+#  for qemu/UNIX domain socket mode
+#
+# PASTA - Pack A Subtle Tap Abstraction
+#  for network namespace/tap device mode
+#
+# test/pasta_options/netns_only - Check --netns-only handling
+
+htools	unshare grep
+
+test	--netns-only skips id mapping configuration
+set	OUT __STATEDIR__/netns-only.out
+set	ERR __STATEDIR__/netns-only.err
+
+passt	unshare -r -- ./pasta -q --netns-only -- echo TEST > __OUT__ 2> __ERR__
+check	grep -qx TEST __OUT__
+check	[ ! -s __ERR__ ]
diff --git a/test/run b/test/run
index f858e55..c4073cc 100755
--- a/test/run
+++ b/test/run
@@ -85,6 +85,7 @@ run() {
 
 	setup pasta_options
 	test pasta_options/log_to_file
+	test pasta_options/netns_only
 	teardown pasta_options
 
 	setup build