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, 31 insertions, 0 deletions

diff --git a/sql/sql_class.h b/sql/sql_class.h
index 023367cb747..5155ffe0603 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -2341,6 +2341,18 @@ public:
     Protected with LOCK_thd_data mutex.
   */
   void set_query(char *query_arg, uint32 query_length_arg);
+  void set_current_user_used() { current_user_used= TRUE; }
+  bool is_current_user_used() { return current_user_used; }
+  void clean_current_user_used() { current_user_used= FALSE; }
+  void get_definer(LEX_USER *definer);
+  void set_invoker(const LEX_STRING *user, const LEX_STRING *host)
+  {
+    invoker_user= *user;
+    invoker_host= *host;
+  }
+  LEX_STRING get_invoker_user() { return invoker_user; }
+  LEX_STRING get_invoker_host() { return invoker_host; }
+  bool has_invoker() { return invoker_user.length > 0; }
 private:
   /** The current internal error handler for this thread, or NULL. */
   Internal_error_handler *m_internal_handler;
@@ -2360,6 +2372,25 @@ private:
     tree itself is reused between executions and thus is stored elsewhere.
   */
   MEM_ROOT main_mem_root;
+
+  /**
+    It will be set TURE if CURRENT_USER() is called in account management
+    statements or default definer is set in CREATE/ALTER SP, SF, Event,
+    TRIGGER or VIEW statements.
+
+    Current user will be binlogged into Query_log_event if current_user_used
+    is TRUE; It will be stored into invoker_host and invoker_user by SQL thread.
+   */
+  bool current_user_used;
+
+  /**
+    It points to the invoker in the Query_log_event.
+    SQL thread use it as the default definer in CREATE/ALTER SP, SF, Event,
+    TRIGGER or VIEW statements or current user in account management
+    statements if it is not NULL.
+   */
+  LEX_STRING invoker_user;
+  LEX_STRING invoker_host;
 };