From ea187cfd4297e262328b7c376c920850cb23353d Mon Sep 17 00:00:00 2001
From: "bell@sanja.is.com.ua" <>
Date: Sun, 14 Sep 2003 22:12:55 +0300
Subject: [PATCH] fixed proccesing global LIMIT in last SELECT of UNION

---
 mysql-test/r/subselect.result |  5 +++--
 mysql-test/r/union.result     |  4 ++--
 mysql-test/t/subselect.test   |  1 +
 sql/sql_parse.cc              |  4 ++++
 sql/sql_union.cc              | 32 ++++++++++++++++++++++----------
 5 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/mysql-test/r/subselect.result b/mysql-test/r/subselect.result
index 6cac5a9bc6c..703360dc7b5 100644
--- a/mysql-test/r/subselect.result
+++ b/mysql-test/r/subselect.result
@@ -1046,8 +1046,9 @@ t1	CREATE TABLE `t1` (
 ) TYPE=MyISAM CHARSET=latin1
 drop table t1;
 CREATE TABLE t1 SELECT (SELECT 1 as a UNION SELECT 1+1 limit 1,1) as a;
-Warnings:
-Warning	1262	Data truncated, NULL supplied to NOT NULL column 'a' at row 1
+select * from t1;
+a
+2
 SHOW CREATE TABLE t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
diff --git a/mysql-test/r/union.result b/mysql-test/r/union.result
index 2e962190762..952ed566132 100644
--- a/mysql-test/r/union.result
+++ b/mysql-test/r/union.result
@@ -409,7 +409,7 @@ found_rows()
 SELECT SQL_CALC_FOUND_ROWS * FROM t1 UNION SELECT * FROM t2 LIMIT 2,2;
 a
 3
-5
+4
 select found_rows();
 found_rows()
 6
@@ -423,7 +423,7 @@ found_rows()
 5
 SELECT * FROM t1 UNION SELECT * FROM t2 ORDER BY a desc LIMIT 1;
 a
-3
+5
 (SELECT * FROM t1 ORDER by a) UNION ALL (SELECT * FROM t2 ORDER BY a) ORDER BY A desc LIMIT 4;
 a
 5
diff --git a/mysql-test/t/subselect.test b/mysql-test/t/subselect.test
index ef46ba7d12c..c6a574bae62 100644
--- a/mysql-test/t/subselect.test
+++ b/mysql-test/t/subselect.test
@@ -606,6 +606,7 @@ CREATE TABLE t1 SELECT * FROM (SELECT 1 as a,(SELECT a+0)) a;
 SHOW CREATE TABLE t1;
 drop table t1;
 CREATE TABLE t1 SELECT (SELECT 1 as a UNION SELECT 1+1 limit 1,1) as a;
+select * from t1;
 SHOW CREATE TABLE t1;
 drop table t1;
 
diff --git a/sql/sql_parse.cc b/sql/sql_parse.cc
index d987a4ba8f1..2f770e329a1 100644
--- a/sql/sql_parse.cc
+++ b/sql/sql_parse.cc
@@ -1723,6 +1723,10 @@ mysql_execute_command(THD *thd)
       break;					// Error message is given
     }
 
+    /* 
+       In case of single SELECT unit->global_parameters points on first SELECT
+       TODO: move counters to SELECT_LEX
+    */
     unit->offset_limit_cnt= (ha_rows) unit->global_parameters->offset_limit;
     unit->select_limit_cnt= (ha_rows) (unit->global_parameters->select_limit+
       unit->global_parameters->offset_limit);
diff --git a/sql/sql_union.cc b/sql/sql_union.cc
index 2d7bee54da8..ae596625bf7 100644
--- a/sql/sql_union.cc
+++ b/sql/sql_union.cc
@@ -262,8 +262,23 @@ int st_select_lex_unit::exec()
 	res= sl->join->reinit();
       else
       {
-	offset_limit_cnt= sl->offset_limit;
-	select_limit_cnt= sl->select_limit+sl->offset_limit;
+	if (sl != global_parameters)
+	{
+	  offset_limit_cnt= sl->offset_limit;
+	  select_limit_cnt= sl->select_limit+sl->offset_limit;
+	}
+	else
+	{
+	  offset_limit_cnt= 0;
+	  /*
+	    We can't use LIMIT at this stage if we are using ORDER BY for the
+	    whole query
+	  */
+	  if (sl->order_list.first)
+	    select_limit_cnt= HA_POS_ERROR;
+	  else
+	    select_limit_cnt= sl->select_limit+sl->offset_limit;
+	}
 	if (select_limit_cnt < sl->select_limit)
 	  select_limit_cnt= HA_POS_ERROR;		// no limit
 
@@ -352,14 +367,11 @@ int st_select_lex_unit::exec()
     {
       ulong options= thd->options;
       thd->lex.current_select= fake_select_lex;
-      if (select_cursor->braces)
-      {
-	offset_limit_cnt= global_parameters->offset_limit;
-	select_limit_cnt= global_parameters->select_limit +
-	  global_parameters->offset_limit;
-	if (select_limit_cnt < global_parameters->select_limit)
-	  select_limit_cnt= HA_POS_ERROR;		// no limit
-      }
+      offset_limit_cnt= global_parameters->offset_limit;
+      select_limit_cnt= global_parameters->select_limit +
+	global_parameters->offset_limit;
+      if (select_limit_cnt < global_parameters->select_limit)
+	select_limit_cnt= HA_POS_ERROR;		// no limit
       if (select_limit_cnt == HA_POS_ERROR)
 	options&= ~OPTION_FOUND_ROWS;
       else if (found_rows_for_union && !describe)