Fixed bug in multiple-table-delete where some rows was not deleted

mysql-test/r/delete.result:
  Test case for bug in multiple-table-delete where some rows was not deleted
mysql-test/t/delete.test:
  Test case for bug in multiple-table-delete where some rows was not deleted
sql/item_subselect.cc:
  Code cleanup
sql/opt_range.cc:
  Code cleanup
sql/sql_delete.cc:
  Fixed bug in multiple-table-delete where some rows was not deleted
  This happend when the first table-to-delete-from was not the the table that was scanned.
  Fixed this by only doing 'delete-on-the-fly' for the first table.
  Fixed also some wrong error handling in multi-table-delete

mysql-test/r/delete.result

-drop table if exists t1,t11,t12,t2;
+drop table if exists t1,t2,t3,t11,t12;
 CREATE TABLE t1 (a tinyint(3), b tinyint(5));
 INSERT INTO t1 VALUES (1,1);
 INSERT LOW_PRIORITY INTO t1 VALUES (1,2);
@@ -172,3 +172,23 @@ a
 0
 2
 DROP TABLE t1;
+CREATE TABLE t1 (a int not null,b int not null);
+CREATE TABLE t2 (a int not null, b int not null, primary key (a,b));
+CREATE TABLE t3 (a int not null, b int not null, primary key (a,b));
+insert into t1 values (1,1),(2,1),(1,3);
+insert into t2 values (1,1),(2,2),(3,3);
+insert into t3 values (1,1),(2,1),(1,3);
+select * from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
+a	b	a	b	a	b
+1	1	1	1	1	1
+2	1	2	2	2	1
+1	3	1	1	1	3
+explain select * from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	3	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	8	NULL	3	Using where; Using index
+1	SIMPLE	t3	index	PRIMARY	PRIMARY	8	NULL	3	Using where; Using index
+delete t2.*,t3.* from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
+select * from t3;
+a	b
+drop table t1,t2,t3;

mysql-test/t/delete.test

@@ -3,7 +3,7 @@
 #
 
 --disable_warnings
-drop table if exists t1,t11,t12,t2;
+drop table if exists t1,t2,t3,t11,t12;
 --enable_warnings
 CREATE TABLE t1 (a tinyint(3), b tinyint(5));
 INSERT INTO t1 VALUES (1,1);
@@ -152,3 +152,20 @@ INSERT INTO t1 VALUES (0),(1),(2);
 DELETE FROM t1 WHERE t1.a > 0 ORDER BY t1.a LIMIT 1;
 SELECT * FROM t1;
 DROP TABLE t1;
+
+#
+# Test of multi-delete where we are not scanning the first table
+#
+
+CREATE TABLE t1 (a int not null,b int not null);
+CREATE TABLE t2 (a int not null, b int not null, primary key (a,b));
+CREATE TABLE t3 (a int not null, b int not null, primary key (a,b));
+insert into t1 values (1,1),(2,1),(1,3);
+insert into t2 values (1,1),(2,2),(3,3);
+insert into t3 values (1,1),(2,1),(1,3);
+select * from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
+explain select * from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
+delete t2.*,t3.* from t1,t2,t3 where t1.a=t2.a AND t2.b=t3.a and t1.b=t3.b;
+# This should be empty
+select * from t3;
+drop table t1,t2,t3;

sql/item_subselect.cc

@@ -773,9 +773,8 @@ Item_in_subselect::single_value_transformer(JOIN *join,
 					    Comp_creator *func)
 {
   Item_subselect::trans_res result= RES_ERROR;
-  DBUG_ENTER("Item_in_subselect::single_value_transformer");
-
   SELECT_LEX *select_lex= join->select_lex;
+  DBUG_ENTER("Item_in_subselect::single_value_transformer");
 
   /*
     Check that the right part of the subselect contains no more than one

sql/opt_range.cc

@@ -7957,7 +7957,7 @@ void QUICK_GROUP_MIN_MAX_SELECT::update_key_stat()
   max_used_key_length= real_prefix_len;
   if (min_max_ranges.elements > 0)
   {
-    QUICK_RANGE *cur_range= 0;
+    QUICK_RANGE *cur_range;
     if (have_min)
     { /* Check if the right-most range has a lower boundary. */
       get_dynamic(&min_max_ranges, (gptr)&cur_range,
@@ -7965,7 +7965,7 @@ void QUICK_GROUP_MIN_MAX_SELECT::update_key_stat()
       if (!(cur_range->flag & NO_MIN_RANGE))
       {
         max_used_key_length+= min_max_arg_len;
-        ++used_key_parts;
+        used_key_parts++;
         return;
       }
     }
@@ -7975,7 +7975,7 @@ void QUICK_GROUP_MIN_MAX_SELECT::update_key_stat()
       if (!(cur_range->flag & NO_MAX_RANGE))
       {
         max_used_key_length+= min_max_arg_len;
-        ++used_key_parts;
+        used_key_parts++;
         return;
       }
     }
@@ -7983,7 +7983,7 @@ void QUICK_GROUP_MIN_MAX_SELECT::update_key_stat()
   else if (have_min && min_max_arg_part && min_max_arg_part->field->is_null())
   {
     max_used_key_length+= min_max_arg_len;
-    ++used_key_parts;
+    used_key_parts++;
   }
 }
 

sql/sql_class.h

@@ -1854,7 +1854,8 @@ class multi_delete :public select_result_interceptor
   ha_rows deleted, found;
   uint num_of_tables;
   int error;
-  bool do_delete, transactional_tables, normal_tables;
+  bool do_delete, transactional_tables, normal_tables, delete_while_scanning;
+
 public:
   multi_delete(THD *thd, TABLE_LIST *dt, uint num_of_tables);
   ~multi_delete();
@@ -1862,7 +1863,7 @@ class multi_delete :public select_result_interceptor
   bool send_data(List<Item> &items);
   bool initialize_tables (JOIN *join);
   void send_error(uint errcode,const char *err);
-  int  do_deletes (bool from_send_error);
+  int  do_deletes();
   bool send_eof();
 };
 

sql/sql_delete.cc

@@ -411,7 +411,7 @@ multi_delete::multi_delete(THD *thd_arg, TABLE_LIST *dt,
     num_of_tables(num_of_tables_arg), error(0),
     do_delete(0), transactional_tables(0), normal_tables(0)
 {
-  tempfiles = (Unique **) sql_calloc(sizeof(Unique *) * (num_of_tables-1));
+  tempfiles= (Unique **) sql_calloc(sizeof(Unique *) * num_of_tables);
 }
 
 
@@ -441,6 +441,7 @@ multi_delete::initialize_tables(JOIN *join)
     tables_to_delete_from|= walk->table->map;
 
   walk= delete_tables;
+  delete_while_scanning= 1;
   for (JOIN_TAB *tab=join->join_tab, *end=join->join_tab+join->tables;
        tab < end;
        tab++)
@@ -460,10 +461,25 @@ multi_delete::initialize_tables(JOIN *join)
       else
 	normal_tables= 1;
     }
+    else if ((tab->type != JT_SYSTEM && tab->type != JT_CONST) &&
+             walk == delete_tables)
+    {
+      /*
+        We are not deleting from the table we are scanning. In this
+        case send_data() shouldn't delete any rows a we may touch
+        the rows in the deleted table many times
+      */
+      delete_while_scanning= 0;
+    }
   }
   walk= delete_tables;
   tempfiles_ptr= tempfiles;
-  for (walk= walk->next_local ;walk ;walk= walk->next_local)
+  if (delete_while_scanning)
+  {
+    table_being_deleted= delete_tables;
+    walk= walk->next_local;
+  }
+  for (;walk ;walk= walk->next_local)
   {
     TABLE *table=walk->table;
     *tempfiles_ptr++= new Unique (refpos_order_cmp,
@@ -482,12 +498,12 @@ multi_delete::~multi_delete()
        table_being_deleted;
        table_being_deleted= table_being_deleted->next_local)
   {
-    TABLE *t=table_being_deleted->table;
-    free_io_cache(t);				// Alloced by unique
-    t->no_keyread=0;
+    TABLE *table= table_being_deleted->table;
+    free_io_cache(table);                       // Alloced by unique
+    table->no_keyread=0;
   }
 
-  for (uint counter= 0; counter < num_of_tables-1; counter++)
+  for (uint counter= 0; counter < num_of_tables; counter++)
   {
     if (tempfiles[counter])
       delete tempfiles[counter];
@@ -497,14 +513,15 @@ multi_delete::~multi_delete()
 
 bool multi_delete::send_data(List<Item> &values)
 {
-  int secure_counter= -1;
+  int secure_counter= delete_while_scanning ? -1 : 0;
+  TABLE_LIST *del_table;
   DBUG_ENTER("multi_delete::send_data");
 
-  for (table_being_deleted= delete_tables;
-       table_being_deleted;
-       table_being_deleted= table_being_deleted->next_local, secure_counter++)
+  for (del_table= delete_tables;
+       del_table;
+       del_table= del_table->next_local, secure_counter++)
   {
-    TABLE *table=table_being_deleted->table;
+    TABLE *table= del_table->table;
 
     /* Check if we are using outer join and we didn't find the row */
     if (table->status & (STATUS_NULL_ROW | STATUS_DELETED))
@@ -515,7 +532,8 @@ bool multi_delete::send_data(List<Item> &values)
 
     if (secure_counter < 0)
     {
-      /* If this is the table we are scanning */
+      /* We are scanning the current table */
+      DBUG_ASSERT(del_table == table_being_deleted);
       if (table->triggers &&
           table->triggers->process_triggers(thd, TRG_EVENT_DELETE,
                                             TRG_ACTION_BEFORE, FALSE))
@@ -529,8 +547,7 @@ bool multi_delete::send_data(List<Item> &values)
                                               TRG_ACTION_AFTER, FALSE))
 	  DBUG_RETURN(1);
       }
-      else if (!table_being_deleted->next_local ||
-	       table_being_deleted->table->file->has_transactions())
+      else
       {
 	table->file->print_error(error,MYF(0));
 	DBUG_RETURN(1);
@@ -541,7 +558,7 @@ bool multi_delete::send_data(List<Item> &values)
       error=tempfiles[secure_counter]->unique_add((char*) table->file->ref);
       if (error)
       {
-	error=-1;
+	error= 1;                               // Fatal error
 	DBUG_RETURN(1);
       }
     }
@@ -564,22 +581,24 @@ void multi_delete::send_error(uint errcode,const char *err)
   /* Something already deleted so we have to invalidate cache */
   query_cache_invalidate3(thd, delete_tables, 1);
 
-  /* Below can happen when thread is killed early ... */
-  if (!table_being_deleted)
-    table_being_deleted=delete_tables;
-
   /*
     If rows from the first table only has been deleted and it is
     transactional, just do rollback.
     The same if all tables are transactional, regardless of where we are.
     In all other cases do attempt deletes ...
   */
-  if ((table_being_deleted->table->file->has_transactions() &&
-       table_being_deleted == delete_tables) || !normal_tables)
+  if ((table_being_deleted == delete_tables &&
+       table_being_deleted->table->file->has_transactions()) ||
+      !normal_tables)
     ha_rollback_stmt(thd);
   else if (do_delete)
   {
-    VOID(do_deletes(1));
+    /*
+      We have to execute the recorded do_deletes() and write info into the
+      error log
+    */
+    error= 1;
+    send_eof();
   }
   DBUG_VOID_RETURN;
 }
@@ -592,27 +611,20 @@ void multi_delete::send_error(uint errcode,const char *err)
 	1 error
 */
 
-int multi_delete::do_deletes(bool from_send_error)
+int multi_delete::do_deletes()
 {
   int local_error= 0, counter= 0;
   DBUG_ENTER("do_deletes");
+  DBUG_ASSERT(do_delete);
 
-  if (from_send_error)
-  {
-    /* Found out table number for 'table_being_deleted*/
-    for (TABLE_LIST *aux= delete_tables;
-	 aux != table_being_deleted;
-	 aux= aux->next_local)
-      counter++;
-  }
-  else
-    table_being_deleted = delete_tables;
-
-  do_delete= 0;
+  do_delete= 0;                                 // Mark called
   if (!found)
     DBUG_RETURN(0);
-  for (table_being_deleted= table_being_deleted->next_local;
-       table_being_deleted;
+
+  table_being_deleted= (delete_while_scanning ? delete_tables->next_local :
+                        delete_tables);
+ 
+  for (; table_being_deleted;
        table_being_deleted= table_being_deleted->next_local, counter++)
   { 
     TABLE *table = table_being_deleted->table;
@@ -674,7 +686,7 @@ bool multi_delete::send_eof()
   thd->proc_info="deleting from reference tables";
 
   /* Does deletes for the last n - 1 tables, returns 0 if ok */
-  int local_error= do_deletes(0);		// returns 0 if success
+  int local_error= do_deletes();		// returns 0 if success
 
   /* reset used flags */
   thd->proc_info="end";