MDEV-14551 Can't find record in table on multi-table update with ORDER BY

preserve positions if the multi-update join is using tmp table:

* store positions in the tmp table if needed
  JOIN::add_fields_for_current_rowid()

* take positions from the tmp table, not from file->position():
  multi_update::prepare2()

12 files changed, 218 insertions, 12 deletions

diff --git a/mysql-test/main/multi_update.result b/mysql-test/main/multi_update.result
index 45239f6e090..c40de47668a 100644
--- a/mysql-test/main/multi_update.result
+++ b/mysql-test/main/multi_update.result
@@ -968,3 +968,75 @@ NULL	6
 7	7
 8	8
 drop table t1, t2;
+create table t1 (i int) engine=memory;
+insert t1 values (1),(2);
+create table t2 (f int) engine=myisam;
+insert t2 values (1),(2);
+explain update t1, t2 set f = 126 order by f limit 2;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using temporary; Using filesort
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	
+update t1, t2 set f = 126 order by f limit 2;
+select * from t2;
+f
+126
+2
+drop table t1, t2;
+create table t0(a int);
+insert t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t1 (a int, b int, c int, key(a));
+insert t1 select a,a,a from t0;
+create table t2 as select * from t1;
+create table t3 as select * from t1;
+select * from t1, t2 where t1.a=t2.a and t1.b in (select b from t3 where t3.c<=t2.c) order by t2.c, t1.c limit 5;
+a	b	c	a	b	c
+0	0	0	0	0	0
+1	1	1	1	1	1
+2	2	2	2	2	2
+3	3	3	3	3	3
+4	4	4	4	4	4
+set optimizer_switch='firstmatch=off';
+explain update t1, t2 set t2.c=1 where t1.a=t2.a and t1.b in (select b from t3 where t3.c< t2.c) order by t2.c, t1.c limit 10;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	PRIMARY	t2	ALL	NULL	NULL	NULL	NULL	10	Using temporary; Using filesort
+1	PRIMARY	t1	ALL	a	NULL	NULL	NULL	10	Using where
+1	PRIMARY	t3	ALL	NULL	NULL	NULL	NULL	10	Using where; Start temporary; End temporary
+update t1, t2 set t2.c=1 where t1.a=t2.a and t1.b in (select b from t3 where t3.c<=t2.c) order by t2.c, t1.c limit 5;
+select * from t2;
+a	b	c
+0	0	1
+1	1	1
+2	2	1
+3	3	1
+4	4	1
+5	5	5
+6	6	6
+7	7	7
+8	8	8
+9	9	9
+set optimizer_switch=default;
+drop table t0,t1,t2,t3;
+create table t0 (x int);
+create table t1 (a int);
+create table t2 (b int, c int default 0);
+insert t0 (x) values (0),(10);
+insert t1 (a) values (1), (2);
+insert t2 (b) values (1), (2);
+create view v1 as select t2.b,t2.c from t1, t2
+where t1.a=t2.b and t2.b < 3 with check option;
+select * from t0 join v1 on (x=c);
+x	b	c
+0	1	0
+0	2	0
+explain update v1,t0 set c=1 where b=1 and x=c order by x,b limit 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	2	Using where; Using temporary; Using filesort
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	2	Using where
+1	SIMPLE	t0	ALL	NULL	NULL	NULL	NULL	2	Using where
+update v1,t0 set c=1 where b<3 and x=c order by x,b limit 1;
+select * from v1;
+b	c
+1	1
+2	0
+drop view v1;
+drop table t0, t1,t2;
diff --git a/mysql-test/main/multi_update.test b/mysql-test/main/multi_update.test
index 5feebe87a5a..42e34d1e4a1 100644
--- a/mysql-test/main/multi_update.test
+++ b/mysql-test/main/multi_update.test
@@ -914,3 +914,49 @@ update t1 set c1=NULL;
 update t1, t2 set t1.c1=t2.c3 where t1.c3=t2.c3 order by t1.c3 desc limit 2;
 select * from t1;
 drop table t1, t2;
+
+#
+# MDEV-14551 Can't find record in table on multi-table update with ORDER BY
+#
+
+# simple test with multi-update and Using temporary:
+create table t1 (i int) engine=memory;
+insert t1 values (1),(2);
+create table t2 (f int) engine=myisam;
+insert t2 values (1),(2);
+explain update t1, t2 set f = 126 order by f limit 2;
+update t1, t2 set f = 126 order by f limit 2;
+select * from t2;
+drop table t1, t2;
+
+# test with DuplicateElimination
+# (so that keep_current_rowid is set for DuplicateElimination too)
+create table t0(a int);
+insert t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t1 (a int, b int, c int, key(a));
+insert t1 select a,a,a from t0;
+create table t2 as select * from t1;
+create table t3 as select * from t1;
+select * from t1, t2 where t1.a=t2.a and t1.b in (select b from t3 where t3.c<=t2.c) order by t2.c, t1.c limit 5;
+set optimizer_switch='firstmatch=off';
+explain update t1, t2 set t2.c=1 where t1.a=t2.a and t1.b in (select b from t3 where t3.c< t2.c) order by t2.c, t1.c limit 10;
+update t1, t2 set t2.c=1 where t1.a=t2.a and t1.b in (select b from t3 where t3.c<=t2.c) order by t2.c, t1.c limit 5;
+select * from t2;
+set optimizer_switch=default;
+drop table t0,t1,t2,t3;
+
+# test WITH CHECK OPTION
+create table t0 (x int);
+create table t1 (a int);
+create table t2 (b int, c int default 0);
+insert t0 (x) values (0),(10);
+insert t1 (a) values (1), (2);
+insert t2 (b) values (1), (2);
+create view v1 as select t2.b,t2.c from t1, t2
+  where t1.a=t2.b and t2.b < 3 with check option;
+select * from t0 join v1 on (x=c);
+explain update v1,t0 set c=1 where b=1 and x=c order by x,b limit 1;
+update v1,t0 set c=1 where b<3 and x=c order by x,b limit 1;
+select * from v1;
+drop view v1;
+drop table t0, t1,t2;
diff --git a/sql/item.cc b/sql/item.cc
index bfd5ed78bf8..dcdd353162a 100644
--- a/sql/item.cc
+++ b/sql/item.cc
@@ -6797,6 +6797,11 @@ fast_field_copier Item_field::setup_fast_field_copier(Field *to)
   return to->get_fast_field_copier(field);
 }
 
+void Item_field::save_in_result_field(bool no_conversions)
+{
+  bool unused;
+  save_field_in_field(field, &unused, result_field, no_conversions);
+}
 
 /**
   Set a field's value from a item.
diff --git a/sql/item.h b/sql/item.h
index bd5c85e6140..7f2569d54d0 100644
--- a/sql/item.h
+++ b/sql/item.h
@@ -2997,8 +2997,7 @@ public:
                                          cond_equal_ref);
   }
   bool is_result_field() { return false; }
-  void set_result_field(Field *field_arg) {}
-  void save_in_result_field(bool no_conversions) { }
+  void save_in_result_field(bool no_conversions);
   Item *get_tmp_table_item(THD *thd);
   bool collect_item_field_processor(void * arg);
   bool add_field_to_set_processor(void * arg);
diff --git a/sql/item_func.h b/sql/item_func.h
index 376f8fc16a1..d6bb0f18700 100644
--- a/sql/item_func.h
+++ b/sql/item_func.h
@@ -70,7 +70,7 @@ public:
 		  SP_CONTAINS_FUNC,SP_OVERLAPS_FUNC,
 		  SP_STARTPOINT,SP_ENDPOINT,SP_EXTERIORRING,
 		  SP_POINTN,SP_GEOMETRYN,SP_INTERIORRINGN, SP_RELATE_FUNC,
-                  NOT_FUNC, NOT_ALL_FUNC,
+                  NOT_FUNC, NOT_ALL_FUNC, TEMPTABLE_ROWID,
                   NOW_FUNC, NOW_UTC_FUNC, SYSDATE_FUNC, TRIG_COND_FUNC,
                   SUSERVAR_FUNC, GUSERVAR_FUNC, COLLATE_FUNC,
                   EXTRACT_FUNC, CHAR_TYPECAST_FUNC, FUNC_SP, UDF_FUNC,
diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index 1132a947587..eb084c3f58d 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -1765,6 +1765,7 @@ public:
   Field *create_tmp_field(bool group, TABLE *table)
   { return create_table_field_from_handler(table); }
   String *val_str(String *str);
+  enum Functype functype() const { return  TEMPTABLE_ROWID; }
   const char *func_name() const { return "<rowid>"; }
   void fix_length_and_dec();
   Item *get_copy(THD *thd)
diff --git a/sql/sql_class.h b/sql/sql_class.h
index bba1740b46f..0ff588a6d38 100644
--- a/sql/sql_class.h
+++ b/sql/sql_class.h
@@ -4981,7 +4981,7 @@ public:
     unit= u;
     return 0;
   }
-  virtual int prepare2(void) { return 0; }
+  virtual int prepare2(JOIN *join) { return 0; }
   /*
     Because of peculiarities of prepared statements protocol
     we need to know number of columns in the result set (if
@@ -5225,7 +5225,7 @@ class select_insert :public select_result_interceptor {
 		enum_duplicates duplic, bool ignore);
   ~select_insert();
   int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
-  virtual int prepare2(void);
+  virtual int prepare2(JOIN *join);
   virtual int send_data(List<Item> &items);
   virtual void store_values(List<Item> &values);
   virtual bool can_rollback_data() { return 0; }
@@ -5277,7 +5277,7 @@ public:
   // Needed for access from local class MY_HOOKS in prepare(), since thd is proteted.
   const THD *get_thd(void) { return thd; }
   const HA_CREATE_INFO *get_create_info() { return create_info; };
-  int prepare2(void) { return 0; }
+  int prepare2(JOIN *join) { return 0; }
 
 private:
   TABLE *create_table_from_items(THD *thd,
@@ -5961,6 +5961,7 @@ public:
   int prepare(List<Item> &list, SELECT_LEX_UNIT *u);
   int send_data(List<Item> &items);
   bool initialize_tables (JOIN *join);
+  int prepare2(JOIN *join);
   int  do_updates();
   bool send_eof();
   inline ha_rows num_found() const { return found; }
diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index d36d9aa82d2..9cb6a88fd4d 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -3786,7 +3786,7 @@ select_insert::prepare(List<Item> &values, SELECT_LEX_UNIT *u)
     0   OK
 */
 
-int select_insert::prepare2(void)
+int select_insert::prepare2(JOIN *)
 {
   DBUG_ENTER("select_insert::prepare2");
   if (thd->lex->current_select->options & OPTION_BUFFER_RESULT &&
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index f8d3fb778e3..91d01a31181 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -2671,6 +2671,25 @@ bool JOIN::add_having_as_table_cond(JOIN_TAB *tab)
 }
 
 
+bool JOIN::add_fields_for_current_rowid(JOIN_TAB *cur, List<Item> *table_fields)
+{
+  /*
+    this will not walk into semi-join materialization nests but this is ok
+    because we will never need to save current rowids for those.
+  */
+  for (JOIN_TAB *tab=join_tab; tab < cur; tab++)
+  {
+    if (!tab->keep_current_rowid)
+      continue;
+    Item *item= new (thd->mem_root) Item_temptable_rowid(tab->table);
+    item->fix_fields(thd, 0);
+    table_fields->push_back(item, thd->mem_root);
+    cur->tmp_table_param->func_count++;
+  }
+  return 0;
+}
+
+
 /**
   Set info for aggregation tables
 
@@ -3278,6 +3297,8 @@ JOIN::create_postjoin_aggr_table(JOIN_TAB *tab, List<Item> *table_fields,
 
   if (!(tab->tmp_table_param= new TMP_TABLE_PARAM(tmp_table_param)))
     DBUG_RETURN(true);
+  if (tmp_table_keep_current_rowid)
+    add_fields_for_current_rowid(tab, table_fields);
   tab->tmp_table_param->skip_create_table= true;
   TABLE* table= create_tmp_table(thd, tab->tmp_table_param, *table_fields,
                                  table_group, distinct,
@@ -3672,7 +3693,7 @@ bool JOIN::prepare_result(List<Item> **columns_list)
       select_lex->handle_derived(thd->lex, DT_CREATE))
     goto err;
 
-  if (result->prepare2())
+  if (result->prepare2(this))
     goto err;
 
   if ((select_lex->options & OPTION_SCHEMA_TABLE) &&
@@ -3809,7 +3830,7 @@ void JOIN::exec_inner()
     }
     columns_list= &procedure_fields_list;
   }
-  if (result->prepare2())
+  if (result->prepare2(this))
     DBUG_VOID_RETURN;
 
   if (!tables_list && (table_count || !select_lex->with_sum_func) &&
@@ -26225,7 +26246,7 @@ bool JOIN::change_result(select_result *new_result, select_result *old_result)
   {
     result= new_result;
     if (result->prepare(fields_list, select_lex->master_unit()) ||
-        result->prepare2())
+        result->prepare2(this))
       DBUG_RETURN(true); /* purecov: inspected */
     DBUG_RETURN(false);
   }
diff --git a/sql/sql_select.h b/sql/sql_select.h
index 20c2370d650..2cc47f6ec3b 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -1438,6 +1438,9 @@ public:
   
   enum { QEP_NOT_PRESENT_YET, QEP_AVAILABLE, QEP_DELETED} have_query_plan;
 
+  // if keep_current_rowid=true, whether they should be saved in temporary table
+  bool tmp_table_keep_current_rowid;
+
   /*
     Additional WHERE and HAVING predicates to be considered for IN=>EXISTS
     subquery transformation of a JOIN object.
@@ -1543,6 +1546,7 @@ public:
     pushdown_query= 0;
     original_join_tab= 0;
     explain= NULL;
+    tmp_table_keep_current_rowid= 0;
 
     all_fields= fields_arg;
     if (&fields_list != &fields_arg)      /* Avoid valgrind-warning */
@@ -1776,6 +1780,7 @@ private:
   void cleanup_item_list(List<Item> &items) const;
   bool add_having_as_table_cond(JOIN_TAB *tab);
   bool make_aggr_tables_info();
+  bool add_fields_for_current_rowid(JOIN_TAB *cur, List<Item> *fields);
 };
 
 enum enum_with_bush_roots { WITH_BUSH_ROOTS, WITHOUT_BUSH_ROOTS};
diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 346b21c0a53..8450a98ce3c 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -499,14 +499,14 @@ void select_union_recursive::cleanup()
 bool select_union_direct::change_result(select_result *new_result)
 {
   result= new_result;
-  return (result->prepare(unit->types, unit) || result->prepare2());
+  return (result->prepare(unit->types, unit) || result->prepare2(NULL));
 }
 
 
 bool select_union_direct::postponed_prepare(List<Item> &types)
 {
   if (result != NULL)
-    return (result->prepare(types, unit) || result->prepare2());
+    return (result->prepare(types, unit) || result->prepare2(NULL));
   else
     return false;
 }
diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index 829bfa546ce..a8b86448d5e 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -2198,10 +2198,66 @@ loop_end:
       DBUG_RETURN(1);
     tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE);
   }
+  join->tmp_table_keep_current_rowid= TRUE;
   DBUG_RETURN(0);
 }
 
 
+static TABLE *item_rowid_table(Item *item)
+{
+  if (item->type() != Item::FUNC_ITEM)
+    return NULL;
+  Item_func *func= (Item_func *)item;
+  if (func->functype() != Item_func::TEMPTABLE_ROWID)
+    return NULL;
+  Item_temptable_rowid *itr= (Item_temptable_rowid *)func;
+  return itr->table;
+}
+
+
+/*
+  multi_update stores a rowid and new field values for every updated row in a
+  temporary table (one temporary table per updated table).  These rowids are
+  obtained via Item_temptable_rowid's by calling handler::position().  But if
+  the join is resolved via a temp table, rowids cannot be obtained from
+  handler::position() in the multi_update::send_data().  So, they're stored in
+  the join's temp table (JOIN::add_fields_for_current_rowid()) and here we
+  replace Item_temptable_rowid's (that would've done handler::position()) with
+  Item_field's (that will simply take the corresponding field value from the
+  temp table).
+*/
+int multi_update::prepare2(JOIN *join)
+{
+  if (!join->need_tmp || !join->tmp_table_keep_current_rowid)
+    return 0;
+
+  // there cannot be many tmp tables in multi-update
+  JOIN_TAB *tmptab= join->join_tab + join->exec_join_tab_cnt();
+
+  for (Item **it= tmptab->tmp_table_param->items_to_copy; *it ; it++)
+  {
+    TABLE *tbl= item_rowid_table(*it);
+    if (!tbl)
+      continue;
+    for (uint i= 0; i < table_count; i++)
+    {
+      for (Item **it2= tmp_table_param[i].items_to_copy; *it2; it2++)
+      {
+        if (item_rowid_table(*it2) != tbl)
+          continue;
+        Item *fld= new (thd->mem_root)
+                        Item_field(thd, (*it)->get_tmp_table_field());
+        if (!fld)
+          return 1;
+        fld->set_result_field((*it2)->get_tmp_table_field());
+        *it2= fld;
+      }
+    }
+  }
+  return 0;
+}
+
+
 multi_update::~multi_update()
 {
   TABLE_LIST *table;