libssh2_sftp_fstat_ex returns LIBSSH2_ERROR_SFTP_PROTOCOL on a file of zero size

[rgbrt]

Describe the bug
libssh2_sftp_fstat_ex (both the get and set variants) returns LIBSSH2_ERROR_SFTP_PROTOCOL on a newly created file of zero size

To Reproduce

1. Open/Create file which does not exist on the server. This works as confirmed with libssh2_session_last_errno(session)

sftp_handle = libssh2_sftp_open_ex(sftp_session, sftppath.c_str(),
                                (unsigned int)strlen(sftppath.c_str()),
                                LIBSSH2_FXF_WRITE|LIBSSH2_FXF_CREAT,
                                LIBSSH2_SFTP_S_IRUSR|LIBSSH2_SFTP_S_IWUSR, LIBSSH2_SFTP_OPENFILE)

2. Run fstat (either variant). It returns -31 which corresponds to LIBSSH2_ERROR_SFTP_PROTOCOL.

        LIBSSH2_SFTP_ATTRIBUTES attrs;
        libssh2_sftp_fstat_ex(sftp_handle, &attrs, 0);
        //or
        attrs.flags = LIBSSH2_SFTP_ATTR_SIZE;
        attrs.filesize = 0;
        libssh2_sftp_fstat_ex(sftp_handle, &attrs, 1);

Expected behavior
Should have been successful

Version (please complete the following information):

• OS and version: Rocky Linux 4.18.0-372.19.1.el8_6.x86_64
• libssh2 version: 1.10
• crypto backend: OpenSSL

[vszakats]

Can you post the log output with debug logging enabled?

[vszakats]

We merged a patch that may be related to this: #1019