bk commit into 5.0 tree (sergefp:1.2513) BUG#30324

[Sergey Petrunia]

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5.0 repository of psergey. When psergey does a push these changes will
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ChangeSet@stripped, 2007-09-14 14:53:13+04:00, sergefp@stripped +3 -0
  BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
  - The bug was caused by COUNT(DISTINCT ...) code using Unique object in 
    a way that assumed that BIT(N) column occupies a contiguous space in
    temp_table->record[0] buffer. 
  - The fix is to make COUNT(DISTINCT ...) code instruct create_tmp_table to
    create temporary table with column of type BIGINT, not BIT(N).

  mysql-test/r/type_bit.result@stripped, 2007-09-14 14:53:11+04:00, sergefp@stripped +15 -0
    BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
    - Testcase

  mysql-test/t/type_bit.test@stripped, 2007-09-14 14:53:11+04:00, sergefp@stripped +14 -0
    BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
    - Testcase

  sql/item_sum.cc@stripped, 2007-09-14 14:53:11+04:00, sergefp@stripped +17 -0
    BUG#30324: Grouping queries with COUNT(DISTINCT bit column) return wrong results
    - Make COUNT(DISTINCT ...) code instruct create_tmp_table to create 
      temporary table with BIGINT, not BIT(N) column.

diff -Nrup a/mysql-test/r/type_bit.result b/mysql-test/r/type_bit.result
--- a/mysql-test/r/type_bit.result	2007-08-17 18:29:10 +04:00
+++ b/mysql-test/r/type_bit.result	2007-09-14 14:53:11 +04:00
@@ -657,4 +657,19 @@ b
 #
 #
 DROP TABLE t1;
+CREATE TABLE t1 (a int, b bit(2));
+INSERT INTO t1 VALUES (3, 2), (2, 3), (2, 0), (3, 2), (3, 1);
+SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
+COUNT(DISTINCT b)
+2
+2
+DROP TABLE t1;
+create table t2 (a int, b bit(2), c char(10));
+INSERT INTO t2 VALUES (3, 2, 'two'), (2, 3, 'three'), (2, 0, 'zero'), 
+(3, 2, 'two'), (3, 1, 'one');
+SELECT COUNT(DISTINCT b,c) FROM t2 GROUP BY a;
+COUNT(DISTINCT b,c)
+2
+2
+DROP TABLE t2;
 End of 5.0 tests
diff -Nrup a/mysql-test/t/type_bit.test b/mysql-test/t/type_bit.test
--- a/mysql-test/t/type_bit.test	2007-08-17 18:28:48 +04:00
+++ b/mysql-test/t/type_bit.test	2007-09-14 14:53:11 +04:00
@@ -304,4 +304,18 @@ SELECT b FROM t1 GROUP BY b;
 --disable_metadata
 DROP TABLE t1;
 
+#
+# BUG#30324 Wrong query result for COUNT(DISTINCT(bit_column))
+#
+CREATE TABLE t1 (a int, b bit(2));
+INSERT INTO t1 VALUES (3, 2), (2, 3), (2, 0), (3, 2), (3, 1);
+SELECT COUNT(DISTINCT b) FROM t1 GROUP BY a;
+DROP TABLE t1;
+
+create table t2 (a int, b bit(2), c char(10));
+INSERT INTO t2 VALUES (3, 2, 'two'), (2, 3, 'three'), (2, 0, 'zero'), 
+                      (3, 2, 'two'), (3, 1, 'one');
+SELECT COUNT(DISTINCT b,c) FROM t2 GROUP BY a;
+DROP TABLE t2;
+
 --echo End of 5.0 tests
diff -Nrup a/sql/item_sum.cc b/sql/item_sum.cc
--- a/sql/item_sum.cc	2007-07-19 20:20:54 +04:00
+++ b/sql/item_sum.cc	2007-09-14 14:53:11 +04:00
@@ -2464,6 +2464,23 @@ bool Item_sum_count_distinct::setup(THD 
   count_field_types(select_lex, tmp_table_param, list, 0);
   tmp_table_param->force_copy_fields= force_copy_fields;
   DBUG_ASSERT(table == 0);
+  /*
+    Make create_tmp_table() convert BIT columns to BIGINT.
+    This is needed because BIT fields store parts of their data in table's
+    null bits, and we don't have methods to compare two table records, which
+    is needed by Unique which is used when HEAP table is used.
+  */
+  {
+    List_iterator_fast<Item> li(list);
+    Item *item;
+    while ((item= li++))
+    {
+      if (item->type() == Item::FIELD_ITEM &&
+          ((Item_field*)item)->field->type() == FIELD_TYPE_BIT)
+        item->marker=4;
+    }
+  }
+
   if (!(table= create_tmp_table(thd, tmp_table_param, list, (ORDER*) 0, 1,
 				0,
 				(select_lex->options | thd->options),