MDEV-28429 audit plugin report OOOOO.

Few initializations to the connection_info structure added. I think they can be removed if we are sure the bug was fixed.

Author: Alexey Botchkov

plugin/server_audit/server_audit.c

@@ -15,7 +15,7 @@
 
 
 #define PLUGIN_VERSION 0x104
-#define PLUGIN_STR_VERSION "1.4.13"
+#define PLUGIN_STR_VERSION "1.4.14"
 
 #define _my_thread_var loc_thread_var
 
@@ -945,7 +945,19 @@ static unsigned long long query_counter= 1;
 
 static struct connection_info *get_loc_info(MYSQL_THD thd)
 {
+ /*
+ This is the original code and supposed to be returned
+ bach to this as the MENT-1438 is finally understood/resolved.
  return (struct connection_info *) THDVAR(thd, loc_info);
+ */
+ struct connection_info *ci= (struct connection_info *) THDVAR(thd, loc_info);
+ if ((size_t) ci->user_length > sizeof(ci->user))
+ {
+ ci->user_length= 0;
+ ci->host_length= 0;
+ ci->ip_length= 0;
+ }
+ return ci;
 }
 
 
@@ -1373,6 +1385,16 @@ static size_t log_header(char *message, size_t message_len,
  host= userip;
  }
 
+ /*
+ That was added to find the possible cause of the MENT-1438.
+ Supposed to be removed after that.
+ */
+ if (username_len > 1024)
+ {
+ username= "unknown_user";
+ username_len= (unsigned int) strlen(username);
+ }
+
  if (output_type == OUTPUT_SYSLOG)
  return my_snprintf(message, message_len,
  "%.*s,%.*s,%.*s,%d,%lld,%s",