2 files changed, 37 insertions, 0 deletions
diff --git a/mysql-test/main/range_innodb.result b/mysql-test/main/range_innodb.result
index 30161a2711d..8774a623826 100644
--- a/mysql-test/main/range_innodb.result
+++ b/mysql-test/main/range_innodb.result
@@ -80,3 +80,21 @@ ERROR HY000: Table definition has changed, please retry transaction
 DROP TABLE t0,t1;
 set @@global.debug_dbug="-d";
 set @@optimizer_switch= @optimizer_switch_save;
+#
+# MDEV-19634: Assertion `0' failed in row_sel_convert_mysql_key_to_innobase,
+# [Warning] InnoDB: Using a partial-field key prefix in search
+#
+CREATE TABLE t1 (
+pk INT,
+a VARCHAR(1),
+b INT,
+PRIMARY KEY (pk),
+KEY (a,b)
+) ENGINE=InnoDB;
+INSERT INTO t1 VALUES (1,'a',1),(2,'b',2);
+explain SELECT a FROM t1 WHERE pk < 0 AND a <= 'w' and b > 0;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	PRIMARY,a	a	9	NULL	2	Using where; Using index
+SELECT a FROM t1 WHERE pk < 0 AND a <= 'w' and b > 0;
+a
+drop table t1;
diff --git a/mysql-test/main/range_innodb.test b/mysql-test/main/range_innodb.test
index a17ef3f1146..2c225df27fe 100644
--- a/mysql-test/main/range_innodb.test
+++ b/mysql-test/main/range_innodb.test
@@ -87,3 +87,22 @@ select * from t1 where a=10 and b=10;
 DROP TABLE t0,t1;
 set @@global.debug_dbug="-d";
 set @@optimizer_switch= @optimizer_switch_save;
+
+--echo #
+--echo # MDEV-19634: Assertion `0' failed in row_sel_convert_mysql_key_to_innobase,
+--echo # [Warning] InnoDB: Using a partial-field key prefix in search
+--echo #
+
+CREATE TABLE t1 (
+    pk INT,
+    a VARCHAR(1),
+    b INT,
+    PRIMARY KEY (pk),
+    KEY (a,b)
+) ENGINE=InnoDB;
+
+INSERT INTO t1 VALUES (1,'a',1),(2,'b',2);
+
+explain SELECT a FROM t1 WHERE pk < 0 AND a <= 'w' and b > 0;
+SELECT a FROM t1 WHERE pk < 0 AND a <= 'w' and b > 0;
+drop table t1;