Implement the first user of the deferred set_conf entries.

Testing with simrotorez shows the correct sequence of actions and
  correct commands being received.

include/hamlib/rotator.h

@@ -629,6 +629,7 @@ struct rot_state {
     hamlib_port_t rotport;  /*!< Rotator port (internal use). */
     hamlib_port_t rotport2;  /*!< 2nd Rotator port (internal use). */
     rig_ptr_t *pstrotator_handler_priv_data;
+    deferred_config_header_t config_queue;
 };
 
 

rotators/rotorez/rotorez.c

@@ -29,6 +29,7 @@
  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
 
 #include <stdio.h>
 #include <stdlib.h>          /* Standard library definitions */
@@ -39,6 +40,7 @@
 #include "serial.h"
 #include "register.h"
 #include "iofunc.h"
+#include "misc.h"
 
 #include "rotorez.h"
 
@@ -1087,12 +1089,21 @@ static int rotorez_rot_set_conf(ROT *rot, hamlib_token_t token, const char *val)
         return -RIG_EINVAL;
     }
 
-    rig_debug(RIG_DEBUG_TRACE, "%s: c = %c, *val = %c\n", __func__, c, *val);
     SNPRINTF(cmdstr, sizeof(cmdstr), "%c", c);
 
     rig_debug(RIG_DEBUG_TRACE, "%s: cmdstr = %s, *val = %c\n",
               __func__, cmdstr, *val);
 
+    /*
+     * We cannot send anything to the rotator if it isn't open yet.
+     * Queue any set_conf commands and let rot_open reprocess them
+     *  after it has done it's job.
+     */
+    if (!ROTSTATE(rot)->comm_state)
+    {
+	err = queue_deferred_config(&ROTSTATE(rot)->config_queue, token, val);
+	return err;
+    }
     err = rotorez_send_priv_cmd(rot, cmdstr);
 
     if (err != RIG_OK)

src/rotator.c

@@ -377,6 +377,7 @@ int HAMLIB_API rot_open(ROT *rot)
     hamlib_port_t *rotp2 = ROTPORT2(rot);
     int status;
     int net1, net2, net3, net4, port;
+    deferred_config_item_t *item;
 
     rot_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
 
@@ -522,6 +523,22 @@ int HAMLIB_API rot_open(ROT *rot)
 
     rs->comm_state = 1;
 
+    /*
+     * Now that the rotator port is officially opened, we can
+     *  send the deferred configuration info.
+     */
+    while ((item = rs->config_queue.first))
+      {
+	rs->config_queue.first = item->next;
+	status = rot_set_conf(rot, item->token, item->value);
+	free(item->value);
+	free(item);
+	if (status != RIG_OK)
+	{
+	  return status;
+	}
+      }
+    
     /*
      * Maybe the backend has something to initialize
      * In case of failure, just close down and report error code.