config: Invert sense of _is_invisible, and rename to is_listable()

src/app/config/config.c

@@ -8128,7 +8128,7 @@ getinfo_helper_config(control_connection_t *conn,
     smartlist_t *vars = config_mgr_list_vars(get_options_mgr());
     SMARTLIST_FOREACH_BEGIN(vars, const config_var_t *, var) {
       /* don't tell controller about invisible options */
-      if (config_var_is_invisible(var))
+      if (! config_var_is_listable(var))
         continue;
       const char *type = struct_var_get_typename(&var->member);
       if (!type)

src/app/config/confparse.c

@@ -534,11 +534,17 @@ config_var_is_contained(const config_var_t *var)
 {
   return struct_var_is_contained(&var->member);
 }
+
+/**
+ * Return true iff variable <b>var</b> should appear on list of variables
+ * given to the controller or the CLI.
+ **/
 bool
-config_var_is_invisible(const config_var_t *var)
+config_var_is_listable(const config_var_t *var)
 {
-  return (var->flags & CVFLAG_INVISIBLE) != 0;
+  return (var->flags & CVFLAG_INVISIBLE) == 0;
 }
+
 bool
 config_var_is_dumpable(const config_var_t *var)
 {

src/app/config/confparse.h

@@ -191,7 +191,7 @@ void warn_deprecated_option(const char *what, const char *why);
 
 bool config_var_is_settable(const config_var_t *var);
 bool config_var_is_contained(const config_var_t *var);
-bool config_var_is_invisible(const config_var_t *var);
+bool config_var_is_listable(const config_var_t *var);
 bool config_var_is_dumpable(const config_var_t *var);
 
 /* Helper macros to compare an option across two configuration objects */