POSIX: CHECK() that file_util::ScopedFD fulfills promise.

base/file_util_unittest.cc

Index: base/file_util_unittest.cc
diff --git a/base/file_util_unittest.cc b/base/file_util_unittest.cc
index e7c43ff4533ff42c5b057b5b2a29b3be5b5ca65a..e410c6463ec05a04fcbdfeeb7908473b6ab08aae 100644
--- a/base/file_util_unittest.cc
+++ b/base/file_util_unittest.cc
@@ -12,6 +12,12 @@
 #include <winioctl.h>
 #endif
 
+#if defined(OS_POSIX)
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#endif
+
 #include <algorithm>
 #include <fstream>
 #include <set>
@@ -2463,6 +2469,43 @@ TEST_F(FileUtilTest, NonExistentContentUriTest) {
 }
 #endif
 
+TEST(ScopedFD, ScopedFDDoesClose) {
+  int fds[2];
+  char c = 0;
+  ASSERT_EQ(0, pipe(fds));
+  const int write_end = fds[1];
+  file_util::ScopedFDCloser read_end_closer(fds);
+  {
+    file_util::ScopedFDCloser write_end_closer(fds + 1);
+  }
+  // This is the only thread. This file descriptor should no longer be valid.
+  int ret = close(write_end);
+  EXPECT_EQ(-1, ret);
+  EXPECT_EQ(EBADF, errno);
+  // Make sure read(2) won't block.
+  ASSERT_EQ(0, fcntl(fds[0], F_SETFL, O_NONBLOCK));
+  // Reading the pipe should EOF.
+  EXPECT_EQ(0, read(fds[0], &c, 1));
+}
+
+#if defined(GTEST_HAS_DEATH_TEST)
+void CloseWithScopedFD(int fd) {
+  file_util::ScopedFDCloser fd_closer(&fd);
+}
+#endif
+
+TEST(ScopedFD, ScopedFDCrashesOnCloseFailure) {
+  int fds[2];
+  ASSERT_EQ(0, pipe(fds));
+  file_util::ScopedFDCloser read_end_closer(fds);
+  EXPECT_EQ(0, IGNORE_EINTR(close(fds[1])));
+#if defined(GTEST_HAS_DEATH_TEST)
+  // This is the only thread. This file descriptor should no longer be valid.
+  // Trying to close it should crash. This is important for security.
+  EXPECT_DEATH(CloseWithScopedFD(fds[1]), "");
+#endif
+}
+
 #endif  // defined(OS_POSIX)
 
 }  // namespace