Fix UNION

New faster list iterators
Change list code to be simpler and faster
Optimize count(distinct)
New error messages for UNION
Make create_tmp_table more general to be usable by UNION


Docs/manual.texi:
  Changelog
include/mysqld_error.h:
  Add new error messages needed for UNION
mysql-test/r/union.result:
  New tests for UNION
mysql-test/t/analyse.test:
  Add missing drop table
mysql-test/t/union.test:
  new tests for UNION
sql/Makefile.am:
  Change name of sql_unions.cc to sql_union.cc
sql/item.cc:
  Use List_iterator_fast
sql/item_cmpfunc.cc:
  Use List_iterator_fast
sql/item_func.cc:
  Use List_iterator_fast
sql/item_sum.cc:
  Use List_iterator_fast
  Optimize count(distinct)
  Cleanup of indentation and comments
sql/item_sum.h:
  Optimize count(distinct)
sql/key.cc:
  Use List_iterator_fast
sql/mysql_priv.h:
  Add new option bits
sql/opt_sum.cc:
  Use List_iterator_fast
sql/share/Makefile.am:
  Add 'fix_errors' label
sql/share/czech/errmsg.txt:
  Add new error messages needed for UNION
sql/share/danish/errmsg.txt:
  Add new error messages needed for UNION
sql/share/dutch/errmsg.txt:
  Add new error messages needed for UNION
sql/share/english/errmsg.txt:
  Add new error messages needed for UNION
sql/share/estonian/errmsg.txt:
  Add new error messages needed for UNION
sql/share/french/errmsg.txt:
  Add new error messages needed for UNION
sql/share/german/errmsg.txt:
  Add new error messages needed for UNION
sql/share/greek/errmsg.txt:
  Add new error messages needed for UNION
sql/share/hungarian/errmsg.txt:
  Add new error messages needed for UNION
sql/share/italian/errmsg.txt:
  Add new error messages needed for UNION
sql/share/japanese/errmsg.txt:
  Add new error messages needed for UNION
sql/share/korean/errmsg.txt:
  Add new error messages needed for UNION
sql/share/norwegian-ny/errmsg.txt:
  Add new error messages needed for UNION
sql/share/norwegian/errmsg.txt:
  Add new error messages needed for UNION
sql/share/polish/errmsg.txt:
  Add new error messages needed for UNION
sql/share/portuguese/errmsg.txt:
  Add new error messages needed for UNION
sql/share/romanian/errmsg.txt:
  Add new error messages needed for UNION
sql/share/russian/errmsg.txt:
  Add new error messages needed for UNION
sql/share/slovak/errmsg.txt:
  Add new error messages needed for UNION
sql/share/spanish/errmsg.txt:
  Add new error messages needed for UNION
sql/share/swedish/errmsg.txt:
  Add new error messages needed for UNION
sql/sql_analyse.cc:
  Use List_iterator_fast
sql/sql_base.cc:
  Use List_iterator_fast
  Add new argument to setup_fields
sql/sql_class.cc:
  Use List_iterator_fast
sql/sql_class.h:
  Create new class for UNION
sql/sql_handler.cc:
  Use List_iterator_fast
sql/sql_insert.cc:
  Use List_iterator_fast
sql/sql_lex.h:
  Cleanup
sql/sql_list.cc:
  Faster iteration of lists
sql/sql_list.h:
  Faster iterations of lists
sql/sql_load.cc:
  Use List_iterator_fast
sql/sql_parse.cc:
  Fix UNION code
sql/sql_select.cc:
  Use List_iterator_fast
  Make create_tmp_table more general to be usable by UNION
sql/sql_select.h:
  Changes to speed up copy_fields()
sql/sql_show.cc:
  Use List_iterator_fast
sql/sql_table.cc:
  Use List_iterator_fast
sql/sql_union.cc:
  Fix UNION code
sql/sql_update.cc:
  Use List_iterator_fast
sql/sql_yacc.yy:
  Fix UNION code

mysql-test/r/union.result

@@ -0,0 +1,60 @@
+a	b
+1	a
+2	b
+3	c
+4	d
+5	f
+6	e
+a	b
+1	a
+2	b
+3	c
+3	c
+3	c
+4	d
+5	f
+6	e
+a	b
+1	a
+2	b
+3	c
+3	c
+3	c
+4	d
+6	e
+5	f
+a	b
+1	a
+2	b
+3	c
+3	c
+3	c
+4	d
+5	f
+6	e
+7	g
+0	#
+0	#
+1	a
+2	b
+3	c
+3	c
+3	c
+4	d
+5	f
+6	e
+7	g
+a	b
+1	a
+2	b
+3	c
+t1	b	count(*)
+t1	a	1
+t1	b	1
+t1	c	2
+t2	c	1
+t2	d	1
+t2	e	1
+t2	f	1
+table	type	possible_keys	key	key_len	ref	rows	Extra
+t2	ALL	NULL	NULL	NULL	NULL	4