From 1688ada0e2ce3bf5e62f1539811f0cfb0d8bc4b6 Mon Sep 17 00:00:00 2001
From: unknown <hf@deer.(none)>
Date: Sat, 21 Jun 2003 16:59:40 +0500
Subject: [PATCH 1/2] Proposed fix for #674

This crash happens in rather exotic case when we try to run
SELECT DISTINCT some_func(SUM(some_field)) GROUP BY another_field;
on a table with single row.
Optimizer marks this table as const, sets group=NULL (with remove_const)
thus, create_tmp_table makes mistake collecting columns for temporary table
and then crashes because the field_count gets less than hidden_columns_count.


sql/sql_select.cc:
  There's several ways to fix this bug.
  This one looks easy and correct to me
---
 sql/sql_select.cc | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 0e8b191e4ef..cb056100e2a 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -453,6 +453,9 @@ mysql_select(THD *thd,TABLE_LIST *tables,List<Item> &fields,COND *conds,
     goto err;
 
   thd->proc_info="preparing";
+
+  select_distinct= select_distinct && (join.const_tables != join.tables);
+
   if (result->initialize_tables(&join))
     goto err;
   if (join.const_table_map != join.found_const_table_map &&

From 8abad215650386dedf0001812f44859009de74ef Mon Sep 17 00:00:00 2001
From: unknown <hf@deer.(none)>
Date: Wed, 25 Jun 2003 17:15:33 +0500
Subject: [PATCH 2/2] Testcase for #674 added

mysql-test/r/sel000100.result:
  Result of the testcase added
mysql-test/t/sel000100.test:
  checking for bug #674 added
---
 mysql-test/r/sel000100.result | 10 ++++++++++
 mysql-test/t/sel000100.test   | 15 +++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/mysql-test/r/sel000100.result b/mysql-test/r/sel000100.result
index f9234815a2b..3ffa4004b84 100644
--- a/mysql-test/r/sel000100.result
+++ b/mysql-test/r/sel000100.result
@@ -26,3 +26,13 @@ ORDER BY link;
 key_link_id	link
 NULL	NULL
 drop table t1,t2;
+CREATE TABLE t1 (
+html varchar(5) default NULL,
+rin int(11) default '0',
+out int(11) default '0'
+) TYPE=MyISAM;
+INSERT INTO t1 VALUES ('1',1,0);
+SELECT DISTINCT html,SUM(out)/(SUM(rin)+1) as 'prod' FROM t1 GROUP BY rin;
+html	prod
+1	0.00
+drop table t1;
diff --git a/mysql-test/t/sel000100.test b/mysql-test/t/sel000100.test
index cedb78b17e7..d587fa4ebd0 100644
--- a/mysql-test/t/sel000100.test
+++ b/mysql-test/t/sel000100.test
@@ -29,3 +29,18 @@ GROUP BY t1.id
 ORDER BY link;
 
 drop table t1,t2;
+
+#
+# test case for #674
+#
+CREATE TABLE t1 (
+  html varchar(5) default NULL,
+  rin int(11) default '0',
+  out int(11) default '0'
+) TYPE=MyISAM;
+
+INSERT INTO t1 VALUES ('1',1,0);
+
+SELECT DISTINCT html,SUM(out)/(SUM(rin)+1) as 'prod' FROM t1 GROUP BY rin;
+
+drop table t1;