sql_select.cc, item_buff.cc, item.h:

  Fixed bug #11088: a crash for queries with GROUP BY a BLOB column
  + COUNT(DISTINCT...) due to an attempt to allocate a too large
  buffer for the BLOB field.
  Now the size of the buffer is limited by max_sort_length.
group_by.test, group_by.result:
  Added a test case for bug #11088.


mysql-test/r/group_by.result:
  Added a test case for bug #11088.
mysql-test/t/group_by.test:
  Added a test case for bug #11088.
sql/item.h:
  Fixed bug #11088: a crash for queries with GROUP BY a BLOB column
  + COUNT(DISTINCT...) due to an attempt to allocate a too large
  buffer for the BLOB fields.
  Now the size of the buffer is limited by max_sort_length.
sql/item_buff.cc:
  Fixed bug #11088: a crash for queries with GROUP BY a BLOB column
  + COUNT(DISTINCT...) due to an attempt to allocate a too large
  buffer for the BLOB fields.
  Now the size of the buffer is limited by max_sort_length.
sql/sql_select.cc:
  Fixed bug #11088: a crash for queries with GROUP BY a BLOB column
  + COUNT(DISTINCT...) due to an attempt to allocate a too large
  buffer for the BLOB fields.
  Now the size of the buffer is limited by max_sort_length.

1 files changed, 17 insertions, 0 deletions

diff --git a/mysql-test/t/group_by.test b/mysql-test/t/group_by.test
index fbd39019e6d..21d5abcc287 100644
--- a/mysql-test/t/group_by.test
+++ b/mysql-test/t/group_by.test
@@ -522,3 +522,20 @@ insert into t1 values(3000000000);
 select * from t1;
 select min(b) from t1;
 drop table t1;
+
+#
+# Test for bug #11088: GROUP BY a BLOB colimn with COUNT(DISTINCT column1) 
+#
+
+CREATE TABLE t1 (id int PRIMARY KEY, user_id int, hostname longtext);
+
+INSERT INTO t1 VALUES
+  (1, 7, 'cache-dtc-af05.proxy.aol.com'),
+  (2, 3, 'what.ever.com'),
+  (3, 7, 'cache-dtc-af05.proxy.aol.com'),
+  (4, 7, 'cache-dtc-af05.proxy.aol.com');
+
+SELECT hostname, COUNT(DISTINCT user_id) as no FROM t1
+  WHERE hostname LIKE '%aol%'
+    GROUP BY hostname;
+