integration test for --list-torrc-options

(This option tests our existing behavior, not necessarily the most
sensible behavior.)

src/test/include.am

@@ -23,7 +23,8 @@ TESTSCRIPTS = \
 	src/test/test_workqueue_pipe.sh \
 	src/test/test_workqueue_pipe2.sh \
 	src/test/test_workqueue_socketpair.sh \
-	src/test/test_switch_id.sh
+	src/test/test_switch_id.sh \
+	src/test/test_cmdline.sh
 
 if USE_RUST
 TESTSCRIPTS += \

src/test/test_cmdline.sh

@@ -0,0 +1,48 @@
+#!/bin/sh
+
+umask 077
+set -e
+
+if [ $# -ge 1 ]; then
+  TOR_BINARY="${1}"
+  shift
+else
+  TOR_BINARY="${TESTING_TOR_BINARY:-./src/app/tor}"
+fi
+
+echo "TOR BINARY IS ${TOR_BINARY}"
+
+die() { echo "$1" >&2 ; exit 5; }
+
+echo "A"
+
+DATA_DIR=$(mktemp -d -t tor_cmdline_tests.XXXXXX)
+trap 'rm -rf "$DATA_DIR"' 0
+
+# 1. Test list-torrc-options.
+OUT="${DATA_DIR}/output"
+
+echo "B"
+"${TOR_BINARY}" --list-torrc-options > "$OUT"
+
+echo "C"
+
+# regular options are given.
+grep -i "SocksPort" "$OUT" >/dev/null || die "Did not find SocksPort"
+
+
+echo "D"
+
+# unlisted options are given, since they do not have the NOSET flag.
+grep -i "__SocksPort" "$OUT" > /dev/null || die "Did not find __SocksPort"
+
+echo "E"
+
+# unsettable options are not given.
+if grep -i "DisableIOCP" "$OUT"  /dev/null; then
+    die "Found DisableIOCP"
+fi
+if grep -i "HiddenServiceOptions" "$OUT" /dev/null ; then
+    die "Found HiddenServiceOptions"
+fi
+echo "OK"