Improve cache behavior for yaesu and kenwood

https://github.com/Hamlib/Hamlib/issues/226

rigs/kenwood/kenwood.c

@@ -532,8 +532,8 @@ int kenwood_safe_transaction(RIG *rig, const char *cmd, char *buf,
         return -RIG_EINVAL;
     }
 
-    // if this is an IF; cmd and not the first time through check cache
-    if (strncmp(cmd, "IF;", 3) == 0 && priv->cache_start.tv_sec != 0)
+    // if this is an IF cmd and not the first time through check cache
+    if (strcmp(cmd, "IF") == 0 && priv->cache_start.tv_sec != 0)
     {
         int cache_age_ms;
 
@@ -548,15 +548,14 @@ int kenwood_safe_transaction(RIG *rig, const char *cmd, char *buf,
 
         // else we drop through and do the real IF command
     }
-    else if (cmd[2] != ';')
+
+    if (strlen(cmd) > 2)
     {
         // then we must be setting something so we'll invalidate the cache
         rig_debug(RIG_DEBUG_TRACE, "%s: cache invalidated\n", __func__);
         priv->cache_start.tv_sec = 0;
     }
 
-
-
     memset(buf, 0, buf_size);
 
     if (expected == 0)

rigs/yaesu/newcat.c

@@ -5943,7 +5943,7 @@ int newcat_get_cmd(RIG *rig)
     // this is for WSJT-X/JTDX sequence of v/f/m/t
     // should allow rapid repeat of any call using the IF; cmd
     // Any call that changes something in the IF response should invalidate the cache
-    if (strncmp(priv->cmd_str, "IF;", 2) == 0 && priv->cache_start.tv_sec != 0)
+    if (strcmp(priv->cmd_str, "IF;") == 0 && priv->cache_start.tv_sec != 0)
     {
         int cache_age_ms;
 
@@ -5957,7 +5957,7 @@ int newcat_get_cmd(RIG *rig)
         }
         // we drop through and do the real IF command
     }
-    else if (priv->cmd_str[2] != ';') // then we must be setting something so we'll invalidate the cache
+    if (priv->cmd_str[2] != ';') // then we must be setting something so we'll invalidate the cache
     {
         rig_debug(RIG_DEBUG_TRACE, "%s: cache invalidated\n", __func__);
         priv->cache_start.tv_sec = 0;