Fix for bug #20732: Partial index and long sjis search with '>' fails sometimes

We miss some records sometimes using RANGE method if we have
partial key segments.
Example:
  Create table t1(a char(2), key(a(1)));
  insert into t1 values ('a'), ('xx');
  select a from t1 where a > 'x';
We call index_read() passing 'x' key and HA_READ_AFTER_KEY flag
in the handler::read_range_first() wich is wrong because we have
a partial key segment for the field and might miss records like 'xx'.

Fix: don't use open segments in such a case.

1 files changed, 11 insertions, 1 deletions

diff --git a/mysql-test/t/range.test b/mysql-test/t/range.test
index 9280911df2c..245178d7d4a 100644
--- a/mysql-test/t/range.test
+++ b/mysql-test/t/range.test
@@ -510,4 +510,14 @@ OR ((pk4 =1) AND (((pk1 IN ( 7, 2, 1 ))) OR (pk1 =522)) AND ((pk2 IN ( 0, 2635))
 ) AND (pk3 >=1000000);
 drop table t1, t2;
 
-# End of 4.1 tests
+#
+# Bug #20732: Partial index and long sjis search with '>' fails sometimes
+#
+
+create table t1(a char(2), key(a(1)));
+insert into t1 values ('x'), ('xx');
+explain select a from t1 where a > 'x';
+select a from t1 where a > 'x';
+drop table t1;
+
+--echo End of 4.1 tests