Fixed LP bug #891953.

Due to this bug the function SEL_IMERGE::or_sel_tree_with_checks()
could build an inconsistent merge tree if one of the SEL_TREEs in the
resulting index merge happened to contain a full key range.
This could trigger an assertion failure.

1 files changed, 15 insertions, 0 deletions

diff --git a/mysql-test/t/range_vs_index_merge.test b/mysql-test/t/range_vs_index_merge.test
index f1bf9d9026f..de7e6a0838c 100755
--- a/mysql-test/t/range_vs_index_merge.test
+++ b/mysql-test/t/range_vs_index_merge.test
@@ -1074,6 +1074,21 @@ SELECT * FROM t1
 
 DROP TABLE t1;
 
+#
+# LP bug #891953: always true OR    
+#              
+
+CREATE TABLE t1 (a int PRIMARY KEY, b int, INDEX idx(b));
+INSERT INTO t1 VALUES (167,9999), (168,10000);
+
+EXPLAIN
+SELECT * FROM t1
+  WHERE a BETWEEN 4 AND 5 AND b IN (255,4) OR a IN (2,14,25) OR a!=2;
+SELECT * FROM t1
+  WHERE a BETWEEN 4 AND 5 AND b IN (255,4) OR a IN (2,14,25) OR a!=2;
+
+DROP TABLE t1;
+
 #the following command must be the last one in the file
 set session optimizer_switch='index_merge_sort_intersection=default';