elecraft.c: Quell compiler warning of buffer size

GCC 4.8.x revealed an error in the way the destination buffer size was
calculated for storing the K3 firmware revision.  Now, instead of
declaring the array in the kenwood_priv_data structure, it is declared
as static in elecraft.c and a pointer is now assigned in the
kenwood_priv_data structure.  This allows for proper calculation of the
array size for strncpy().

kenwood/elecraft.c

@@ -41,6 +41,15 @@ static const struct elec_ext_id_str elec_ext_id_str_lst[] = {
 };
 
 
+/* K3 firmware revision level, will be assigned to the fw_rev pointer in
+ * kenwood_priv_data structure at runtime in electraft_open().  The array is
+ * declared here so that the sizeof operator can be used in the call to
+ * elecraft_get_firmware_revision_level() to calculate the exact size of the
+ * array for the call to strncpy().
+ */
+static char k3_fw_rev[KENWOOD_MAX_BUF_LEN];
+
+
 /* Private Elecraft extra levels definitions
  *
  * Token definitions for .cfgparams in rig_caps
@@ -63,7 +72,7 @@ const struct confparams elecraft_ext_levels[] = {
 /* Private function declarations */
 int verify_kenwood_id(RIG *rig, char *id);
 int elecraft_get_extension_level(RIG *rig, const char *cmd, int *ext_level);
-int elecraft_get_firmware_revision_level(RIG *rig, const char *cmd, char *fw_rev);
+int elecraft_get_firmware_revision_level(RIG *rig, const char *cmd, char *fw_rev, size_t fw_rev_sz);
 
 /* Shared backend function definitions */
 
@@ -94,6 +103,12 @@ int elecraft_open(RIG *rig)
 	 */
 	struct kenwood_priv_data *priv = rig->state.priv;
 
+	/* As k3_fw_rev is declared static, it is persistent so the structure
+	 * can point to it.  This way was chosen to allow the compiler to
+	 * calculate the size of the array to resolve a bug found by gcc 4.8.x
+	 */
+	priv->fw_rev = k3_fw_rev;
+
 	/* Use check for "ID017;" to verify rig is reachable */
 	err = verify_kenwood_id(rig, id);
 	if (err != RIG_OK)
@@ -124,7 +139,9 @@ int elecraft_open(RIG *rig)
 		rig_debug(RIG_DEBUG_VERBOSE, "%s: K3 level is %d, %s\n", __func__,
 			priv->k3_ext_lvl, elec_ext_id_str_lst[priv->k3_ext_lvl].id);
 
-		err = elecraft_get_firmware_revision_level(rig, "RVM", priv->k3_fw_rev);
+		err = elecraft_get_firmware_revision_level(rig, "RVM", priv->fw_rev,
+				(sizeof(k3_fw_rev) / sizeof(k3_fw_rev[0])));
+
 		if (err != RIG_OK)
 			return err;
 
@@ -220,7 +237,8 @@ int elecraft_get_extension_level(RIG *rig, const char *cmd, int *ext_level)
 
 /* Determine firmware revision level */
 
-int elecraft_get_firmware_revision_level(RIG *rig, const char *cmd, char *fw_rev)
+int elecraft_get_firmware_revision_level(RIG *rig, const char *cmd,
+                                         char *fw_rev, size_t fw_rev_sz)
 {
 	rig_debug(RIG_DEBUG_VERBOSE, "%s called\n", __func__);
 
@@ -232,23 +250,28 @@ int elecraft_get_firmware_revision_level(RIG *rig, const char *cmd, char *fw_rev
 	char buf[KENWOOD_MAX_BUF_LEN];
 	size_t size = KENWOOD_MAX_BUF_LEN;
 
-	err = kenwood_transaction(rig, cmd, sizeof(cmd), buf, &size);
+	/* Get the actual firmware revision number. */
+	err = kenwood_transaction(rig, cmd, strlen(cmd), buf, &size);
+
 	if (err != RIG_OK) {
-		rig_debug(RIG_DEBUG_VERBOSE, "%s: Cannot get firmeware revision level\n", __func__);
+		rig_debug(RIG_DEBUG_VERBOSE, "%s: Cannot get firmware revision level\n", __func__);
 		return err;
 	}
 
-	/* Get the actual firmware revision number. */
+	/* Now buf[] contains the string from the K3 which includes the command
+	 * and the firmware revision number as:  "RVM04.67".
+	 */
+
 	bufptr = &buf[0];
 
 	/* Skip the command string */
-	bufptr += sizeof(cmd);
+	bufptr += strlen(cmd);
 
-	/* Ignore leading zero's */
+	/* Skip leading zero(s) as the revision number has the format of: "04.67" */
 	while (bufptr && *bufptr == '0') { bufptr++; }
 
 	/* Copy out */
-	strncpy(fw_rev, bufptr, sizeof(bufptr));
+	strncpy(fw_rev, bufptr, fw_rev_sz - 1);
 
 	rig_debug(RIG_DEBUG_VERBOSE, "%s: Elecraft firmware revision is %s\n", __func__, fw_rev);
 

kenwood/k3.c

@@ -606,7 +606,7 @@ int k3_get_level(RIG *rig, vfo_t vfo, setting_t level, value_t *val)
 		 * offers a higher resolution, 0-100 (mine went to 106),
 		 * rawstr value for more precise S-meter reporting.
 		 */
-		retval = strncmp(priv->k3_fw_rev, "4.37", 4);
+		retval = strncmp(priv->fw_rev, "4.37", 4);
 		if (retval < 0) {
 			cal_table_t str_cal = K3_SM_CAL;
 
@@ -715,4 +715,3 @@ int set_rit_xit(RIG *rig, shortfreq_t rit)
 
 	return RIG_OK;
 }
-

kenwood/kenwood.h

@@ -74,9 +74,10 @@ struct kenwood_priv_data {
     int k2_ext_lvl;		/* Initial K2 extension level */
     int k3_ext_lvl;		/* Initial K3 extension level */
     int k2_md_rtty;		/* K2 RTTY mode available flag, 1 = RTTY, 0 = N/A */
-    char k3_fw_rev[KENWOOD_MAX_BUF_LEN]; /* K3 firmware revision level */
+    char *fw_rev;		/* firmware revision level */
 };
 
+
 #define kenwood_caps(rig) ((struct kenwood_priv_caps *)(rig)->caps->priv)