The following statements support the CURRENT_USER() where a user is needed.

DROP USER 
RENAME USER CURRENT_USER() ...
GRANT ... TO CURRENT_USER()
REVOKE ... FROM CURRENT_USER()
ALTER DEFINER = CURRENT_USER() EVENTbut, When these statements are binlogged, CURRENT_USER() just is binlogged
as 'CURRENT_USER()', it is not expanded to the real user name. When slave 
executes the log event, 'CURRENT_USER()' is expand to the user of slave 
SQL thread, but SQL thread's user name always NULL. This breaks the replication.

After this patch, session's user will be written into query log events 
if these statements call CURREN_USER() or 'ALTER EVENT' does not assign a definer.


mysql-test/include/diff_tables.inc:
  Expend its abilities.
  Now it can diff not only in sessions of 'master' and 'slave', but 
  other sessions as well.
sql/log_event.cc:
  session's user will be written into Query_log_event, if is_current_user_used() is TRUE.
  On slave SQL thread, Only thd->invoker is written into Query_log_event,
  if it exists.
sql/sql_acl.cc:
  On slave SQL thread, grantor should copy from thd->invoker, if it exists
sql/sql_class.h:
  On slave SQL thread, thd->invoker is used to store the applying event's
  invoker.

1 files changed, 17 insertions, 6 deletions

diff --git a/sql/sql_acl.cc b/sql/sql_acl.cc
index dd256c70ecb..9640b8db1b2 100644
--- a/sql/sql_acl.cc
+++ b/sql/sql_acl.cc
@@ -194,6 +194,7 @@ static bool compare_hostname(const acl_host_and_ip *host,const char *hostname,
 			     const char *ip);
 static my_bool acl_load(THD *thd, TABLE_LIST *tables);
 static my_bool grant_load(THD *thd, TABLE_LIST *tables);
+static inline void get_grantor(THD *thd, char* grantor);
 
 /*
   Convert scrambled password to binary form, according to scramble type, 
@@ -2704,6 +2705,20 @@ end:
   DBUG_RETURN(result);
 }
 
+static inline void get_grantor(THD *thd, char *grantor)
+{
+  const char *user= thd->security_ctx->user;
+  const char *host= thd->security_ctx->host_or_ip;
+
+#if defined(HAVE_REPLICATION)
+  if (thd->slave_thread && thd->has_invoker())
+  {
+    user= thd->get_invoker_user().str;
+    host= thd->get_invoker_host().str;
+  }
+#endif
+  strxmov(grantor, user, "@", host, NullS);
+}
 
 static int replace_table_table(THD *thd, GRANT_TABLE *grant_table,
 			       TABLE *table, const LEX_USER &combo,
@@ -2718,9 +2733,7 @@ static int replace_table_table(THD *thd, GRANT_TABLE *grant_table,
   uchar user_key[MAX_KEY_LENGTH];
   DBUG_ENTER("replace_table_table");
 
-  strxmov(grantor, thd->security_ctx->user, "@",
-          thd->security_ctx->host_or_ip, NullS);
-
+  get_grantor(thd, grantor);
   /*
     The following should always succeed as new users are created before
     this function is called!
@@ -2850,9 +2863,7 @@ static int replace_routine_table(THD *thd, GRANT_NAME *grant_name,
     DBUG_RETURN(-1);
   }
 
-  strxmov(grantor, thd->security_ctx->user, "@",
-          thd->security_ctx->host_or_ip, NullS);
-
+  get_grantor(thd, grantor);
   /*
     New users are created before this function is called.