Fixed SFTP to be properly BC with version 1 and 2 servers

README

@@ -4,6 +4,8 @@ libssh2 - SSH2 library
 Version 0.9
 -----------
 
+  Fixed SFTP to be properly BC with version 1 and 2 servers.
+
   Fixed libssh2_poll() to recognized closed sessions/channels.
 
   Added libssh2_channel_window_read_ex() and libssh2_channel_window_write_ex()

src/sftp.c

@@ -1032,6 +1032,11 @@ LIBSSH2_API int libssh2_sftp_rename_ex(LIBSSH2_SFTP *sftp,  char *source_filenam
 																				source_filename_len(4) + dest_filename_len(4) + flags(4) */
 	unsigned char *packet, *s, *data;
 
+	if (sftp->version < 2) {
+		libssh2_error(session, LIBSSH2_ERROR_SFTP_PROTOCOL, "Server does not support RENAME", 0);
+		return -1;
+	}
+
 	s = packet = LIBSSH2_ALLOC(session, packet_len);
 	if (!packet) {
 		libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for FXP_RENAME packet", 0);
@@ -1275,6 +1280,12 @@ LIBSSH2_API int libssh2_sftp_symlink_ex(LIBSSH2_SFTP *sftp, const char *path, in
 	unsigned char *packet, *s, *data;
 	unsigned char link_responses[2] = { SSH_FXP_NAME,		SSH_FXP_STATUS	};
 
+	if ((sftp->version < 3) &&
+		(link_type != LIBSSH2_SFTP_REALPATH)) {
+		libssh2_error(session, LIBSSH2_ERROR_SFTP_PROTOCOL, "Server does not support SYMLINK or READLINK", 0);
+		return -1;
+	}
+
 	s = packet = LIBSSH2_ALLOC(session, packet_len);
 	if (!packet) {
 		libssh2_error(session, LIBSSH2_ERROR_ALLOC, "Unable to allocate memory for SYMLINK/READLINK/REALPATH packet", 0);