From 28777046b4dc3decd462a4a7a6d68c168b484635 Mon Sep 17 00:00:00 2001
From: Sergei Petrunia <psergey@askmonty.org>
Date: Thu, 8 Mar 2018 11:43:55 +0100
Subject: [PATCH] MDEV-15245: Assertion `false' failed in
 myrocks::ha_rocksdb::position

Don't call handler->position() if the last call to read a row did
not succeed.
---
 sql/sql_select.cc                             |  2 +-
 .../mysql-test/rocksdb/r/rocksdb_parts.result | 14 ++++++++++++++
 .../mysql-test/rocksdb/t/rocksdb_parts.test   | 19 +++++++++++++++++++
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index 4746f186fe7..6450eb03d4d 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -18724,7 +18724,7 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
       skip_over= FALSE;
     }
 
-    if (join_tab->keep_current_rowid)
+    if (join_tab->keep_current_rowid && !error)
       join_tab->table->file->position(join_tab->table->record[0]);
     
     rc= evaluate_join_record(join, join_tab, error);
diff --git a/storage/rocksdb/mysql-test/rocksdb/r/rocksdb_parts.result b/storage/rocksdb/mysql-test/rocksdb/r/rocksdb_parts.result
index 9ac7243071b..2fde11c2a08 100644
--- a/storage/rocksdb/mysql-test/rocksdb/r/rocksdb_parts.result
+++ b/storage/rocksdb/mysql-test/rocksdb/r/rocksdb_parts.result
@@ -135,3 +135,17 @@ SELECT 1;
 1
 1
 DROP TABLE t1;
+#
+# MDEV-15245: Assertion `false' failed in myrocks::ha_rocksdb::position
+#
+CREATE TABLE t1 (a INT) ENGINE=RocksDB;
+INSERT INTO t1 VALUES (1),(2);
+CREATE TABLE t2 (b INT) ENGINE=RocksDB 
+PARTITION BY RANGE(b) 
+(PARTITION p0 VALUES LESS THAN (1), 
+PARTITION p1 VALUES LESS THAN MAXVALUE);
+INSERT INTO t2 VALUES (NULL),(0);
+CREATE ALGORITHM = MERGE VIEW v1 AS SELECT t2.* FROM t1, t2;
+UPDATE v1 SET b = 5;
+drop view v1;
+drop table t1,t2;
diff --git a/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_parts.test b/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_parts.test
index a0768667385..b8d41ae942a 100644
--- a/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_parts.test
+++ b/storage/rocksdb/mysql-test/rocksdb/t/rocksdb_parts.test
@@ -139,3 +139,22 @@ ALTER TABLE t1 ADD PARTITION PARTITIONS 2;
 SELECT 1;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-15245: Assertion `false' failed in myrocks::ha_rocksdb::position
+--echo #
+CREATE TABLE t1 (a INT) ENGINE=RocksDB;
+INSERT INTO t1 VALUES (1),(2);
+# partitioning
+CREATE TABLE t2 (b INT) ENGINE=RocksDB 
+PARTITION BY RANGE(b) 
+(PARTITION p0 VALUES LESS THAN (1), 
+ PARTITION p1 VALUES LESS THAN MAXVALUE);
+
+
+INSERT INTO t2 VALUES (NULL),(0);
+CREATE ALGORITHM = MERGE VIEW v1 AS SELECT t2.* FROM t1, t2;
+UPDATE v1 SET b = 5;
+
+drop view v1;
+drop table t1,t2;
+