[PATCH v3 2/3] builtins: kill: Add `kill ''` regression test with explicit sigspec

[Chris Down <chris@xxxxxxxxxxxxxx>]

The version without a sigspec can't be added yet because it would still
kill the test runner even in expected-to-fail mode, see workers/45449
for discussion. For the same reason, we use a signal which is non-fatal
by default and unlikely to be sent by someone else, SIGURG, to do the
expected-to-fail case prior to the fix.
---
 Test/B11kill.ztst | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Test/B11kill.ztst b/Test/B11kill.ztst
index c254b0925..fe2da1012 100644
--- a/Test/B11kill.ztst
+++ b/Test/B11kill.ztst
@@ -58,3 +58,12 @@
   )
 1:kill with sigspec only
 ?(eval):kill:2: not enough arguments
+
+# Regression tests: `kill ''` should not result in `kill 0`.
+
+  (
+    trap 'exit 11' URG
+    kill -URG ''
+  )
+1f:kill with empty pid and sigspec should not send signal to current process group
+?(eval):kill:3: illegal pid: 
-- 
2.25.0