diff --git a/mysql-test/r/rpl_bug33931.result b/mysql-test/r/rpl_bug33931.result
new file mode 100644
index 00000000000..519bd73aa6a
--- /dev/null
+++ b/mysql-test/r/rpl_bug33931.result
@@ -0,0 +1,38 @@
+reset master;
+stop slave;
+reset slave;
+start slave;
+show slave status;
+Slave_IO_State	#
+Master_Host	127.0.0.1
+Master_User	root
+Master_Port	MASTER_PORT
+Connect_Retry	1
+Master_Log_File	
+Read_Master_Log_Pos	4
+Relay_Log_File	#
+Relay_Log_Pos	#
+Relay_Master_Log_File	
+Slave_IO_Running	No
+Slave_SQL_Running	No
+Replicate_Do_DB	
+Replicate_Ignore_DB	
+Replicate_Do_Table	
+Replicate_Ignore_Table	
+Replicate_Wild_Do_Table	
+Replicate_Wild_Ignore_Table	
+Last_Errno	0
+Last_Error	
+Skip_Counter	0
+Exec_Master_Log_Pos	0
+Relay_Log_Space	#
+Until_Condition	None
+Until_Log_File	
+Until_Log_Pos	0
+Master_SSL_Allowed	No
+Master_SSL_CA_File	
+Master_SSL_CA_Path	
+Master_SSL_Cert	
+Master_SSL_Cipher	
+Master_SSL_Key	
+Seconds_Behind_Master	#
diff --git a/mysql-test/t/rpl_bug33931-slave.opt b/mysql-test/t/rpl_bug33931-slave.opt
new file mode 100644
index 00000000000..55fe328a41d
--- /dev/null
+++ b/mysql-test/t/rpl_bug33931-slave.opt
@@ -0,0 +1 @@
+--loose-debug=d,simulate_io_slave_error_on_init,simulate_sql_slave_error_on_init
diff --git a/mysql-test/t/rpl_bug33931.test b/mysql-test/t/rpl_bug33931.test
new file mode 100644
index 00000000000..788f79d4c1c
--- /dev/null
+++ b/mysql-test/t/rpl_bug33931.test
@@ -0,0 +1,37 @@
+# Test for 
+# Bug #33931  	assertion at write_ignored_events_info_to_relay_log if init_slave_thread() fails
+# Bug #33932  	assertion at handle_slave_sql if init_slave_thread() fails
+
+source include/have_debug.inc;
+source include/have_log_bin.inc;
+
+connect (master,127.0.0.1,root,,test,$MASTER_MYPORT,);
+connect (slave,127.0.0.1,root,,test,$SLAVE_MYPORT,);
+
+
+connection master;
+reset master;
+
+connection slave;
+--disable_warnings
+stop slave;
+--enable_warnings
+reset slave;
+start slave;
+
+connection master;
+save_master_pos;
+connection slave;
+
+#
+# slave is going to stop because of emulated failures
+# but there won't be any crashes nor asserts hit.
+#
+source include/wait_for_slave_to_stop.inc;
+
+--replace_result $MASTER_MYPORT MASTER_PORT                                     
+--replace_column 1 # 8 # 9 # 23 # 33 #                                          
+query_vertical show slave status;
+
+# no clean-up is needed
+
diff --git a/sql/slave.cc b/sql/slave.cc
index ea0dde942da..4f55d8f7cae 100644
--- a/sql/slave.cc
+++ b/sql/slave.cc
@@ -1507,6 +1507,9 @@ void set_slave_thread_default_charset(THD* thd, Relay_log_info const *rli)
 static int init_slave_thread(THD* thd, SLAVE_THD_TYPE thd_type)
 {
   DBUG_ENTER("init_slave_thread");
+#if !defined(DBUG_OFF)
+  int simulate_error= 0;
+#endif
   thd->system_thread = (thd_type == SLAVE_THD_SQL) ?
     SYSTEM_THREAD_SLAVE_SQL : SYSTEM_THREAD_SLAVE_IO;
   thd->security_ctx->skip_grants();
@@ -1526,10 +1529,17 @@ static int init_slave_thread(THD* thd, SLAVE_THD_TYPE thd_type)
   thd->thread_id= thd->variables.pseudo_thread_id= thread_id++;
   pthread_mutex_unlock(&LOCK_thread_count);
 
+  DBUG_EXECUTE_IF("simulate_io_slave_error_on_init",
+                  simulate_error|= (1 << SLAVE_THD_IO););
+  DBUG_EXECUTE_IF("simulate_sql_slave_error_on_init",
+                  simulate_error|= (1 << SLAVE_THD_SQL););
+#if !defined(DBUG_OFF)
+  if (init_thr_lock() || thd->store_globals() || simulate_error & (1<< thd_type))
+#else
   if (init_thr_lock() || thd->store_globals())
+#endif
   {
     thd->cleanup();
-    delete thd;
     DBUG_RETURN(-1);
   }
   lex_start(thd);
@@ -2229,6 +2239,7 @@ pthread_handler_t handle_slave_io(void *arg)
 
   thd= new THD; // note that contructor of THD uses DBUG_ !
   THD_CHECK_SENTRY(thd);
+  mi->io_thd = thd;
 
   pthread_detach_this_thread();
   thd->thread_stack= (char*) &thd; // remember where our stack is
@@ -2239,7 +2250,6 @@ pthread_handler_t handle_slave_io(void *arg)
     sql_print_error("Failed during slave I/O thread initialization");
     goto err;
   }
-  mi->io_thd = thd;
   pthread_mutex_lock(&LOCK_thread_count);
   threads.append(thd);
   pthread_mutex_unlock(&LOCK_thread_count);
@@ -2530,9 +2540,11 @@ pthread_handler_t handle_slave_sql(void *arg)
 
   thd = new THD; // note that contructor of THD uses DBUG_ !
   thd->thread_stack = (char*)&thd; // remember where our stack is
-
+  rli->sql_thd= thd;
+  
   /* Inform waiting threads that slave has started */
   rli->slave_run_id++;
+  rli->slave_running = 1;
 
   pthread_detach_this_thread();
   if (init_slave_thread(thd, SLAVE_THD_SQL))
@@ -2547,7 +2559,6 @@ pthread_handler_t handle_slave_sql(void *arg)
     goto err;
   }
   thd->init_for_queries();
-  rli->sql_thd= thd;
   thd->temporary_tables = rli->save_temporary_tables; // restore temp tables
   pthread_mutex_lock(&LOCK_thread_count);
   threads.append(thd);
@@ -2560,7 +2571,6 @@ pthread_handler_t handle_slave_sql(void *arg)
     start receiving data so we realize we are not caught up and
     Seconds_Behind_Master grows. No big deal.
   */
-  rli->slave_running = 1;
   rli->abort_slave = 0;
   pthread_mutex_unlock(&rli->run_lock);
   pthread_cond_broadcast(&rli->start_cond);
diff --git a/sql/sql_delete.cc b/sql/sql_delete.cc
index c6435387f44..28450af6c56 100644
--- a/sql/sql_delete.cc
+++ b/sql/sql_delete.cc
@@ -780,8 +780,6 @@ void multi_delete::abort()
     }
     thd->transaction.all.modified_non_trans_table= true;
   }
-  DBUG_ASSERT(!normal_tables || !deleted ||
-              thd->transaction.stmt.modified_non_trans_table);
   DBUG_VOID_RETURN;
 }
 
@@ -899,8 +897,6 @@ bool multi_delete::send_eof()
   {
     query_cache_invalidate3(thd, delete_tables, 1);
   }
-  DBUG_ASSERT(!normal_tables || !deleted ||
-              thd->transaction.stmt.modified_non_trans_table);
   if ((local_error == 0) || thd->transaction.stmt.modified_non_trans_table)
   {
     if (mysql_bin_log.is_open())
diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index 4d075e3308d..22631ee3342 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -1203,7 +1203,7 @@ multi_update::multi_update(TABLE_LIST *table_list,
    tmp_tables(0), updated(0), found(0), fields(field_list),
    values(value_list), table_count(0), copy_field(0),
    handle_duplicates(handle_duplicates_arg), do_update(1), trans_safe(1),
-   transactional_tables(1), ignore(ignore_arg), error_handled(0)
+   transactional_tables(0), ignore(ignore_arg), error_handled(0)
 {}
 
 
@@ -1718,7 +1718,7 @@ void multi_update::abort()
 
   if (trans_safe)
   {
-    DBUG_ASSERT(transactional_tables);
+    DBUG_ASSERT(!updated || transactional_tables);
     (void) ha_autocommit_or_rollback(thd, 1);
   }
   else