UBSAN: client_mpvio_write_packet through pointer to incorrect function

/source/libmariadb/plugins/auth/my_auth.c:94:9: runtime error: call to function client_mpvio_write_packet through pointer to incorrect function type 'int (*)(struct st_plugin_vio *, const unsigned char *, int)'

/source/libmariadb/plugins/auth/my_auth.c:469: note: client_mpvio_write_packet defined here

SUMMARY: UndefinedBehaviorSanitizer: undefined-behavior /source/libmariadb/plugins/auth/my_auth.c:94:9 

line

diff --git a/plugins/auth/my_auth.c b/plugins/auth/my_auth.c

index 215f313..9a91262 100644

--- a/plugins/auth/my_auth.c

+++ b/plugins/auth/my_auth.c

@@ -6,7 +6,7 @@

 #include <mysql/client_plugin.h>

 typedef struct st_mysql_client_plugin_AUTHENTICATION auth_plugin_t;

-static int client_mpvio_write_packet(struct st_plugin_vio*, const uchar*, size_t);

+static int client_mpvio_write_packet(struct st_plugin_vio*, const uchar*, int);

 static int native_password_auth_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql);

 static int dummy_fallback_auth_client(MYSQL_PLUGIN_VIO *vio, MYSQL *mysql __attribute__((unused)));

 extern void read_user_name(char *name);

@@ -16,7 +16,7 @@ extern unsigned char *mysql_net_store_length(unsigned char *packet, ulonglong le

 typedef struct {

   int (*read_packet)(struct st_plugin_vio *vio, uchar **buf);

-  int (*write_packet)(struct st_plugin_vio *vio, const uchar *pkt, size_t pkt_len);

+  int (*write_packet)(struct st_plugin_vio *vio, const uchar *pkt, int pkt_len);

   void (*info)(struct st_plugin_vio *vio, struct st_plugin_vio_info *info);

   /* -= end of MYSQL_PLUGIN_VIO =- */

   MYSQL *mysql;

@@ -465,7 +465,7 @@ static int client_mpvio_read_packet(struct st_plugin_vio *mpv, uchar **buf)

 */

 static int client_mpvio_write_packet(struct st_plugin_vio *mpv,

-                                     const uchar *pkt, size_t pkt_len)

+                                     const uchar *pkt, int pkt_len)

 {

   int res;

   MCPVIO_EXT *mpvio= (MCPVIO_EXT*)mpv;

@@ -473,9 +473,9 @@ static int client_mpvio_write_packet(struct st_plugin_vio *mpv,

   if (mpvio->packets_written == 0)

   {

     if (mpvio->mysql_change_user)

-      res= send_change_user_packet(mpvio, pkt, (int)pkt_len);

+      res= send_change_user_packet(mpvio, pkt, pkt_len);

     else

-      res= send_client_reply_packet(mpvio, pkt, (int)pkt_len);

+      res= send_client_reply_packet(mpvio, pkt, pkt_len);

   }

   else

   {