Merge "Fix bug in WriteStringToFileAtomic"

}

bool WriteStringToFileAtomic(const std::string& content, const std::string& path) {

    std::string tmp_path = path + ".tmp";

    if (!android::base::WriteStringToFile(content, tmp_path)) {

    const std::string tmp_path = path + ".tmp";

    {

        const int flags = O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_BINARY;

        android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(tmp_path.c_str(), flags, 0666)));

        if (fd == -1) {

            PLOG(ERROR) << "Failed to open " << path;

            return false;

        }

        if (!android::base::WriteStringToFd(content, fd)) {

            PLOG(ERROR) << "Failed to write to fd " << fd;

            return false;

        }

        // rename() without fsync() is not safe. Data could still be living on page cache. To ensure

        // atomiticity, call fsync()

        if (fsync(fd) != 0) {

            PLOG(ERROR) << "Failed to fsync " << tmp_path;

        }

    }

    if (rename(tmp_path.c_str(), path.c_str()) == -1) {

        PLOG(ERROR) << "rename failed from " << tmp_path << " to " << path;

        return false;