core: pv - helper function to return empty string

pvapi.c

@@ -608,6 +608,21 @@ int pv_get_null(struct sip_msg *msg, pv_param_t *param, pv_value_t *res)
 	return 0;
 }
 
+/**
+ *
+ */
+int pv_get_strempty(struct sip_msg *msg, pv_param_t *param, pv_value_t *res)
+{
+	if(res==NULL)
+		return -1;
+
+	res->rs = pv_str_empty;
+	res->ri = 0;
+	res->flags = PV_VAL_STR;
+	return 0;
+}
+
+
 /**
  *
  */

pvar.h

@@ -210,6 +210,7 @@ str* pv_cache_get_name(pv_spec_t *spec);
 
 /*! \brief PV helper functions */
 int pv_get_null(struct sip_msg *msg, pv_param_t *param, pv_value_t *res);
+int pv_get_strempty(struct sip_msg *msg, pv_param_t *param, pv_value_t *res);
 
 int pv_get_uintval(struct sip_msg *msg, pv_param_t *param,
 		pv_value_t *res, unsigned int uival);