Changes for multi-table delete and UNION's

mysql-test/t/multi_update.test:
  Made a test feasible. It will last very long time, so I will change 
  it again as soon as Monty pull's it
sql/sql_class.h:
  Some small changes
sql/sql_delete.cc:
  Fixed one bug in my stripping code
sql/sql_parse.cc:
  Additional stuff for UNION's

mysql-test/t/multi_update.test

@@ -2,24 +2,35 @@ drop table if exists t1,t2,t3;
 create table t1(id1 int not null auto_increment primary key, t char(12));
 create table t2(id2 int not null, t char(12), index(id2));
 create table t3(id3 int not null, t char(12), index(id3));
-let $1 = 3;
+let $1 = 10000;
 while ($1)
  {
-  let $2 = 3;
+  let $2 = 5;
   eval insert into t1(t) values ('$1'); 
   while ($2)
    {
      eval insert into t2(id2,t) values ($1,'$2'); 
+     let $3 = 10;
+     while ($3)
+     {
        eval insert into t3(id3,t) values ($1,'$2'); 
+       dec $3;
+     }
      dec $2; 
    }
   dec $1;
  }
 
-select * from t1;
-select * from t2;
-select * from t3;
 
-delete from t1,t2 where t1.id = t2.id and t1.id = 3;
-select * from t1;
-select * from t2;
+delete t1.*, t2.*, t3.*  from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 9500;
+
+check table t1, t2, t3;
+
+select * from t1 where id1 > 9500;
+select * from t2 where id2 > 9500;
+select * from t3 where id3 > 9500;
+
+delete t1, t2, t3  from t1,t2,t3 where t1.id1 = t2.id2 and t2.id2 = t3.id3  and t1.id1 > 500;
+select * from t1 where id1 > 500;
+select * from t2 where id2 > 500;
+select * from t3 where id3 > 500;

sql/sql_class.h

@@ -603,7 +603,8 @@ public:
    byte * dup_checking;
    THD *thd;
    ha_rows deleted;
-   int num_of_tables, error;
+   uint num_of_tables;
+   int error;
    thr_lock_type lock_option;
    bool do_delete;
  public:

sql/sql_delete.cc

@@ -347,7 +347,7 @@ multi_delete::~multi_delete()
   for (uint counter = 0; counter < num_of_tables; counter++)
     if (tempfiles[counter])
 #ifdef SINISAS_STRIP
-//      end_io_cache(tempfiles[counter]);
+      end_io_cache(tempfiles[counter]);
 #else
   delete tempfiles[counter];
 #endif
@@ -549,12 +549,15 @@ static IO_CACHE *strip_duplicates_from_temp (byte *memory_lane, IO_CACHE *ptr, u
   int read_error, write_error, how_many_to_read, total_to_read = *written, pieces_in_memory = 0, mem_count,written_rows;
   int offset = written_rows=*written=0;
   int  mem_pool_size = MEM_STRIP_BUF_SIZE * MAX_REFLENGTH / ref_length;
-  IO_CACHE *tempptr = (IO_CACHE *) sql_alloc(sizeof(IO_CACHE));
   byte dup_record[MAX_REFLENGTH]; memset(dup_record,'\xFF',MAX_REFLENGTH);
   if (reinit_io_cache(ptr,READ_CACHE,0L,0,0))
     return ptr;
+  IO_CACHE *tempptr =  (IO_CACHE *) my_malloc(sizeof(IO_CACHE), MYF(MY_FAE | MY_ZEROFILL));
   if (open_cached_file(tempptr, mysql_tmpdir,TEMP_PREFIX, DISK_BUFFER_SIZE, MYF(MY_WME)))
+  {
+    my_free((gptr) tempptr, MYF (0));
     return ptr;
+  }
   DYNAMIC_ARRAY written_blocks;
   VOID(init_dynamic_array(&written_blocks,sizeof(struct written_block),20,50));
   for (;pieces_in_memory < total_to_read;)
@@ -809,7 +812,7 @@ int  multi_delete::do_deletes (bool from_send_error)
 #ifdef SINISAS_STRIP
       delete select;
 #endif
-      if (error = -1) error = 0;
+      if (error == -1) error = 0;
 #if 0
     }
 #endif

sql/sql_parse.cc

@@ -2437,6 +2437,12 @@ mysql_new_select(LEX *lex)
   SELECT_LEX *select_lex = (SELECT_LEX *)sql_calloc(sizeof(SELECT_LEX));
   lex->select->next=select_lex; 
   lex->select=select_lex; lex->select->select_number = ++select_no;
+  lex->select->item_list = lex->select_lex.item_list; 
+  lex->select->item_list.empty();
+  lex->select->table_list = lex->select_lex.table_list; 
+  lex->select->table_list.elements=0;
+  lex->select->table_list.first=0;
+  lex->select->table_list.next= (byte**) &lex->select->table_list.first;
 }
 
 void