From eab657248dae65ca4d44fb86b9841a307708613b Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Thu, 30 Aug 2018 12:15:56 -0700
Subject: [PATCH] Add a test for poll with null fds.

I don't think we want to *document* this, but since at least
external/curl/lib/select.c is relying on this, we should be careful not
to break it.

Bug: http://b/111850071
Test: ran tests
Change-Id: Ic877250d755a0cb59e77ae38ae5e3949f753dad6
---
 tests/Android.bp    |  1 +
 tests/poll_test.cpp | 57 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)
 create mode 100644 tests/poll_test.cpp

diff --git a/tests/Android.bp b/tests/Android.bp
index ccd11262c..fa66f93b0 100644
--- a/tests/Android.bp
+++ b/tests/Android.bp
@@ -112,6 +112,7 @@ cc_test_library {
         "netinet_ip_icmp_test.cpp",
         "netinet_udp_test.cpp",
         "nl_types_test.cpp",
+        "poll_test.cpp",
         "pthread_test.cpp",
         "pty_test.cpp",
         "regex_test.cpp",
diff --git a/tests/poll_test.cpp b/tests/poll_test.cpp
new file mode 100644
index 000000000..2a3e5e028
--- /dev/null
+++ b/tests/poll_test.cpp
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <gtest/gtest.h>
+
+#include <errno.h>
+#include <poll.h>
+
+TEST(poll, poll_null_fds) {
+  // Because nanosleep(2) is relatively new to POSIX, code sometimes abuses poll.
+  errno = 0;
+  ASSERT_EQ(0, poll(nullptr, 0, 1));
+  ASSERT_EQ(0, errno);
+}
+
+TEST(poll, ppoll_null_fds) {
+  // Because nanosleep(2) is relatively new to POSIX, code sometimes abuses poll.
+  errno = 0;
+  timespec ts = { .tv_nsec = 100 };
+  ASSERT_EQ(0, ppoll(nullptr, 0, &ts, nullptr));
+  ASSERT_EQ(0, errno);
+}
+
+TEST(poll, ppoll64_null_fds) {
+#if __BIONIC__
+  // Because nanosleep(2) is relatively new to POSIX, code sometimes abuses poll.
+  errno = 0;
+  timespec ts = { .tv_nsec = 100 };
+  ASSERT_EQ(0, ppoll64(nullptr, 0, &ts, nullptr));
+  ASSERT_EQ(0, errno);
+#endif
+}