sh/tests: Add tests for SIGINT in non-jobc background commands

If job control is not enabled, background commands shall ignore SIGINT and
SIGQUIT, and it shall be possible to override that ignore in the same shell.

MFC after:	1 week

bin/sh/tests/execution/Makefile

@@ -17,6 +17,8 @@ ${PACKAGE}FILES+=		bg7.0
 ${PACKAGE}FILES+=		bg8.0
 ${PACKAGE}FILES+=		bg9.0
 ${PACKAGE}FILES+=		bg10.0 bg10.0.stdout
+${PACKAGE}FILES+=		bg11.0
+${PACKAGE}FILES+=		bg12.0
 ${PACKAGE}FILES+=		env1.0
 ${PACKAGE}FILES+=		fork1.0
 ${PACKAGE}FILES+=		fork2.0

bin/sh/tests/execution/bg11.0

@@ -0,0 +1,16 @@
+# $FreeBSD$
+
+T=`mktemp -d ${TMPDIR:-/tmp}/sh-test.XXXXXXXX`
+trap 'rm -rf $T' 0
+cd $T || exit 3
+mkfifo fifo1
+# Use a trap, not the default action, since the shell may catch SIGINT and
+# therefore its processing may be delayed.
+{ trap 'exit 5' TERM; read dummy <fifo1; exit 4; } &
+exec 3>fifo1
+kill -INT "$!"
+kill -TERM "$!"
+exec 3>&-
+wait "$!"
+r=$?
+[ "$r" = 5 ]

bin/sh/tests/execution/bg12.0

@@ -0,0 +1,12 @@
+# $FreeBSD$
+
+T=`mktemp -d ${TMPDIR:-/tmp}/sh-test.XXXXXXXX`
+trap 'rm -rf $T' 0
+cd $T || exit 3
+mkfifo fifo1
+{ trap - INT; : >fifo1; sleep 5; exit 4; } &
+: <fifo1
+kill -INT "$!"
+wait "$!"
+r=$?
+[ "$r" -gt 128 ] && [ "$(kill -l "$r")" = INT ]