api doc: gsm48_mi_to_string(): warn of return value implementation
Change-Id: If5e7abd15dddf39cdfad8071f4cd5ca8244eabe0
diff --git a/src/gsm/gsm48.c b/src/gsm/gsm48.c
index ae9a1cf..e684a3c 100644
--- a/src/gsm/gsm48.c
+++ b/src/gsm/gsm48.c
@@ -643,7 +643,10 @@
* \param[in] str_len Length of \a string in bytes
* \param[in] mi Mobile Identity to be stringified
* \param[in] mi_len Length of \a mi in bytes
- * \returns length of string written to \a string */
+ * \returns WARNING: the return value of this function is not well implemented.
+ * Depending on the MI type and amount of output buffer, this may return
+ * the nr of written bytes, or the written strlen(), or the snprintf()
+ * style strlen()-if-the-buffer-were-large-enough. */
int gsm48_mi_to_string(char *string, const int str_len, const uint8_t *mi,
const int mi_len)
{