Bug #58350: 5.5.7-rc compile failed at sp_head.cc

Fixed the references to security_ctx->priv_user
to be real char * pointers instead of a C array name reference.
This is somehow important for some 3d party 
dtrace replacements

sql/sp_head.cc

@@ -3159,7 +3159,7 @@ sp_instr_stmt::exec_core(THD *thd, uint *nextp)
   MYSQL_QUERY_EXEC_START(thd->query(),
                          thd->thread_id,
                          (char *) (thd->db ? thd->db : ""),
-                         thd->security_ctx->priv_user,
+                         &thd->security_ctx->priv_user[0],
                          (char *)thd->security_ctx->host_or_ip,
                          3);
   int res= mysql_execute_command(thd);

sql/sql_connect.cc

@@ -736,7 +736,7 @@ void do_handle_one_connection(THD *thd_arg)
     if (rc)
       goto end_thread;
 
-    MYSQL_CONNECTION_START(thd->thread_id, thd->security_ctx->priv_user,
+    MYSQL_CONNECTION_START(thd->thread_id, &thd->security_ctx->priv_user[0],
                            (char *) thd->security_ctx->host_or_ip);
 
     prepare_new_connection_state(thd);

sql/sql_cursor.cc

@@ -111,7 +111,7 @@ int mysql_open_cursor(THD *thd, select_result *result,
   MYSQL_QUERY_EXEC_START(thd->query(),
                          thd->thread_id,
                          (char *) (thd->db ? thd->db : ""),
-                         thd->security_ctx->priv_user,
+                         &thd->security_ctx->priv_user[0],
                          (char *) thd->security_ctx->host_or_ip,
                          2);
   rc= mysql_execute_command(thd);

sql/sql_parse.cc

@@ -877,7 +877,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
   thd->profiling.start_new_query();
 #endif
   MYSQL_COMMAND_START(thd->thread_id, command,
-                      thd->security_ctx->priv_user,
+                      &thd->security_ctx->priv_user[0],
                       (char *) thd->security_ctx->host_or_ip);
   
   thd->command=command;
@@ -1018,7 +1018,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       break;					// fatal error is set
     MYSQL_QUERY_START(thd->query(), thd->thread_id,
                       (char *) (thd->db ? thd->db : ""),
-                      thd->security_ctx->priv_user,
+                      &thd->security_ctx->priv_user[0],
                       (char *) thd->security_ctx->host_or_ip);
     char *packet_end= thd->query() + thd->query_length();
     /* 'b' stands for 'buffer' parameter', special for 'my_snprintf' */
@@ -1070,7 +1070,7 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
 
       MYSQL_QUERY_START(beginning_of_next_stmt, thd->thread_id,
                         (char *) (thd->db ? thd->db : ""),
-                        thd->security_ctx->priv_user,
+                        &thd->security_ctx->priv_user[0],
                         (char *) thd->security_ctx->host_or_ip);
 
       thd->set_query_and_id(beginning_of_next_stmt, length,
@@ -5489,7 +5489,7 @@ void mysql_parse(THD *thd, char *rawbuf, uint length,
           MYSQL_QUERY_EXEC_START(thd->query(),
                                  thd->thread_id,
                                  (char *) (thd->db ? thd->db : ""),
-                                 thd->security_ctx->priv_user,
+                                 &thd->security_ctx->priv_user[0],
                                  (char *) thd->security_ctx->host_or_ip,
                                  0);
 

sql/sql_prepare.cc

@@ -3759,7 +3759,7 @@ bool Prepared_statement::execute(String *expanded_query, bool open_cursor)
       MYSQL_QUERY_EXEC_START(thd->query(),
                              thd->thread_id,
                              (char *) (thd->db ? thd->db : ""),
-                             thd->security_ctx->priv_user,
+                             &thd->security_ctx->priv_user[0],
                              (char *) thd->security_ctx->host_or_ip,
                              1);
       error= mysql_execute_command(thd);