Extend TS590s firmware defect fixup to both VFOs.

It turns out that either VFO can be incorrectly set in split mode when
the VFO is the TX VFO. The logic has been changed to send an IF; query
and read and set the other VFO if the VFO just set in set_freq is the
TX VFO and the rig is in split.

kenwood/kenwood.c

@@ -864,32 +864,40 @@ int kenwood_set_freq(RIG *rig, vfo_t vfo, freq_t freq)
 	int err = kenwood_simple_cmd(rig, freqbuf);
 
 	struct kenwood_priv_data * priv = rig->state.priv;
-	if (RIG_OK == err && 'B' == vfo_letter && RIG_MODEL_TS590S == rig->caps->rig_model && priv->fw_rev_uint <= 107)
+	if (RIG_OK == err && RIG_MODEL_TS590S == rig->caps->rig_model && priv->fw_rev_uint <= 107 && ('A' == vfo_letter || 'B' == vfo_letter))
 	  {
 	    /* TS590s f/w rev 1.07 or earlier has a defect that means
 	       frequency set on TX VFO in split mode may not be set
-	       correctly when the TX VFO is VFO B.
-
-	       The cleanest way to fix this is to read VFO A and set
-	       VFO A to the read frequency, a redundant sequence that
-	       has the side effect of setting the VFO B frequency
 	       correctly.
 
 	       The symptom of the defect is either TX on the wrong
 	       frequency (i.e. TX on a frequency different from that
-	       showing on VFO B) or no output.
+	       showing on the TX VFO) or no output.
 
-	       Here we don't bother to work out if the rig is in split
-	       mode, we simply always read and set VFO A every time
-	       VFO B has its frequency set. */
+	       We use an IF command to find out if we have just set
+	       the "back" VFO when the rig is in split mode. If we
+	       have; we then read the other VFO and set it to what we
+	       read - a null transaction that fixes the defect. */
 
-	    err = kenwood_safe_transaction (rig, "FA", freqbuf, 16, 14);
+	    err = kenwood_get_if(rig);
 	    if (RIG_OK != err)
 	      {
 		return err;
 	      }
-	    freqbuf[13] = '\0';
-	    err = kenwood_simple_cmd (rig, freqbuf);
+
+	    if ('1' == priv->info[32] && priv->info[30] != ('A' == vfo_letter ? '0' : '1'))
+	      {
+		/* split mode and setting "back" VFO */
+
+		/* set other VFO to whatever it is at currently */
+		err = kenwood_safe_transaction (rig, 'A' == vfo_letter ? "FB" : "FA", freqbuf, 16, 14);
+		if (RIG_OK != err)
+		  {
+		    return err;
+		  }
+		freqbuf[13] = '\0';
+		err = kenwood_simple_cmd (rig, freqbuf);
+	      }
 	  }
 
 	return err;