Fix dup and dup2 in nacl-mounts

libraries/nacl-mounts/test.nacl/DupTest.cc

Index: libraries/nacl-mounts/test.nacl/DupTest.cc
===================================================================
--- libraries/nacl-mounts/test.nacl/DupTest.cc	(revision 0)
+++ libraries/nacl-mounts/test.nacl/DupTest.cc	(revision 0)
@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2012 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "gtest/gtest.h"
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+TEST(DupTest, Simple) {
+  char buff[5];
+
+  int random = open("/dev/random", O_RDONLY);
+  EXPECT_GT(random, 0);
+  int null = open("/dev/null", O_RDWR);
+  EXPECT_GT(null, 0);
+
+  // dup should work and take a reference.
+  int null_copy = dup(null);
+  EXPECT_GT(null_copy, 0);
+  EXPECT_EQ(5, write(null, reinterpret_cast<void*>(buff), 5));
+  EXPECT_EQ(0, read(null, reinterpret_cast<void*>(buff), 5));
+
+  EXPECT_EQ(0, close(null));
+  EXPECT_EQ(5, write(null_copy, reinterpret_cast<void*>(buff), 5));
+  EXPECT_EQ(0, read(null_copy, reinterpret_cast<void*>(buff), 5));
+
+  // dup2 with oldfd == newfd is a no-op.
+  EXPECT_EQ(null_copy, dup2(null_copy, null_copy));
+
+  // dup2 should work on a high fd and take a reference.
+  EXPECT_EQ(99, dup2(null_copy, 99));
+  EXPECT_EQ(5, write(null_copy, reinterpret_cast<void*>(buff), 5));
+  EXPECT_EQ(0, read(null_copy, reinterpret_cast<void*>(buff), 5));
+
+  EXPECT_EQ(0, close(null_copy));
+  EXPECT_EQ(5, write(99, reinterpret_cast<void*>(buff), 5));
+  EXPECT_EQ(0, read(99, reinterpret_cast<void*>(buff), 5));
+
+  // dup2 should close newfd if needbe.
+  EXPECT_EQ(random, dup2(99, random));
+  EXPECT_EQ(5, write(99, reinterpret_cast<void*>(buff), 5));
+  EXPECT_EQ(0, read(99, reinterpret_cast<void*>(buff), 5));
+
+  EXPECT_EQ(0, close(99));
+  EXPECT_EQ(5, write(random, reinterpret_cast<void*>(buff), 5));
+  EXPECT_EQ(0, read(random, reinterpret_cast<void*>(buff), 5));
+}