MDEV-6950 Bad results with joins comparing DATE/DATETIME and INT/DECIMAL/DOUBLE/ENUM/VARCHAR columns

MDEV-6971 Bad results with joins comparing TIME and DOUBLE/DECIMAL columns
Disallow using indexes on non-temporal columns to optimize
ref access, range access and table elimination when the counterpart's
cmp_type is TIME_RESULT, e.g.:
  SELECT * FROM t1 WHERE indexed_int_column=time_expression;
Only index on a temporal column can be used to optimize temporal comparison
operations.

12 files changed, 497 insertions, 0 deletions

diff --git a/mysql-test/r/type_enum.result b/mysql-test/r/type_enum.result
index d373d14c089..bc71d51152d 100644
--- a/mysql-test/r/type_enum.result
+++ b/mysql-test/r/type_enum.result
@@ -1869,3 +1869,44 @@ AVG(f1)
 1.5000
 drop table t1;
 End of 5.3 tests
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-6950 Bad results with joins comparing DATE/DATETIME and INT/ENUM/VARCHAR columns
+#
+CREATE TABLE t1 (c1 DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('2001-01-01');
+CREATE TABLE t2 (c1 ENUM('2001-01-01','2001/01/01'));
+INSERT INTO t2 VALUES ('2001-01-01');
+INSERT INTO t2 VALUES ('2001/01/01');
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+ALTER TABLE t2 ADD PRIMARY KEY(c1);
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+EXPLAIN SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	PRIMARY	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	1	NULL	2	Using where; Using index
+SELECT t1.* FROM t1 LEFT JOIN t2 USING (c1);
+c1
+2001-01-01
+2001-01-01
+# t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 USING (c1);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	1	NULL	2	Using where; Using index
+DROP TABLE t1, t2;
+#
+# End of 10.0 tests
+#
diff --git a/mysql-test/r/type_float.result b/mysql-test/r/type_float.result
index f498b6889a5..57e2660750b 100644
--- a/mysql-test/r/type_float.result
+++ b/mysql-test/r/type_float.result
@@ -465,3 +465,70 @@ f
 1
 2
 DROP TABLE t1;
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-6950 Bad results with joins comparing DATE/DATETIME and INT/DECIMAL/DOUBLE/ENUM/VARCHAR columns
+#
+CREATE TABLE t1 (a DATETIME PRIMARY KEY);
+INSERT INTO t1 VALUES ('1999-01-01 00:00:00');
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES (19990101000000);
+INSERT INTO t2 VALUES (990101000000);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+# t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	8	NULL	2	Using where; Using index
+DROP TABLE t1,t2;
+#
+# MDEV-6971 Bad results with joins comparing TIME and DOUBLE/DECIMAL columns
+#
+CREATE TABLE t1 (a TIME(6) PRIMARY KEY);
+INSERT INTO t1 VALUES ('10:20:30');
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES (102030),(102030.000000001);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+# t2 should NOT be elimitated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	8	NULL	2	Using where; Using index
+DROP TABLE t1,t2;
+#
+# End of 10.0 tests
+#
diff --git a/mysql-test/r/type_newdecimal.result b/mysql-test/r/type_newdecimal.result
index 3f9f234c740..ab075d29e22 100644
--- a/mysql-test/r/type_newdecimal.result
+++ b/mysql-test/r/type_newdecimal.result
@@ -1997,3 +1997,84 @@ select 0.0000000001 mod 1;
 select 0.01 mod 1;
 0.01 mod 1
 0.01
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-6950 Bad results with joins comparing DATE and INT/ENUM/VARCHAR columns
+#
+CREATE TABLE t1 (a DATETIME PRIMARY KEY);
+INSERT INTO t1 VALUES ('1999-01-01 00:00:00');
+CREATE TABLE t2 (a DECIMAL(30,1));
+INSERT INTO t2 VALUES (19990101000000);
+INSERT INTO t2 VALUES (990101000000);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+a
+1999-01-01 00:00:00
+1999-01-01 00:00:00
+# t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	14	NULL	2	Using where; Using index
+DROP TABLE t1,t2;
+#
+# MDEV-6971 Bad results with joins comparing TIME and DOUBLE/DECIMAL columns
+#
+CREATE TABLE t1 (a TIME(6) PRIMARY KEY);
+INSERT INTO t1 VALUES ('10:20:30');
+CREATE TABLE t2 (a DECIMAL(30,10));
+INSERT INTO t2 VALUES (102030),(102030.000000001);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+Warnings:
+Note	1292	Truncated incorrect time value: '102030.0000000000'
+Note	1292	Truncated incorrect time value: '102030.0000000010'
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+Warnings:
+Note	1292	Truncated incorrect time value: '102030.0000000000'
+Note	1292	Truncated incorrect time value: '102030.0000000000'
+Note	1292	Truncated incorrect time value: '102030.0000000010'
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+Warnings:
+Note	1292	Truncated incorrect time value: '102030.0000000000'
+Note	1292	Truncated incorrect time value: '102030.0000000010'
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+a
+10:20:30.000000
+10:20:30.000000
+Warnings:
+Note	1292	Truncated incorrect time value: '102030.0000000000'
+Note	1292	Truncated incorrect time value: '102030.0000000000'
+Note	1292	Truncated incorrect time value: '102030.0000000010'
+# t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	14	NULL	2	Using where; Using index
+DROP TABLE t1,t2;
+#
+# End of 10.0 tests
+#
diff --git a/mysql-test/r/type_set.result b/mysql-test/r/type_set.result
index 09531ec60d5..bc6cbf202c6 100644
--- a/mysql-test/r/type_set.result
+++ b/mysql-test/r/type_set.result
@@ -104,3 +104,44 @@ INSERT INTO t1 ( set_unique_utf8 ) VALUES ( '' );
 ERROR 23000: Duplicate entry '' for key 'set_unique_utf8'
 DROP TABLE t1;
 End of 5.0 tests
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-6950 Bad results with joins compating DATE and INT/ENUM/VARCHAR columns
+#
+CREATE TABLE t1 (c1 DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('2001-01-01');
+CREATE TABLE t2 (c1 SET('2001-01-01','2001/01/01'));
+INSERT INTO t2 VALUES ('2001-01-01');
+INSERT INTO t2 VALUES ('2001/01/01');
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+ALTER TABLE t2 ADD PRIMARY KEY(c1);
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+EXPLAIN SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	PRIMARY	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	1	NULL	2	Using where; Using index
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+# t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	1	NULL	2	Using where; Using index
+DROP TABLE t1, t2;
+#
+# End of 10.0 tests
+#
diff --git a/mysql-test/r/type_uint.result b/mysql-test/r/type_uint.result
index e08605fb237..10aa2f2f393 100644
--- a/mysql-test/r/type_uint.result
+++ b/mysql-test/r/type_uint.result
@@ -14,3 +14,40 @@ this
 0
 4294967295
 drop table t1;
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-6950 Bad results with joins comparing DATE and INT/ENUM/VARCHAR columns
+#
+CREATE TABLE t1 (a DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('1999-01-01');
+CREATE TABLE t2 (a INT UNSIGNED);
+INSERT INTO t2 VALUES (19990101);
+INSERT INTO t2 VALUES (990101);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+a
+1999-01-01
+1999-01-01
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+a
+1999-01-01
+1999-01-01
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+a
+1999-01-01
+1999-01-01
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+a
+1999-01-01
+1999-01-01
+# t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	4	NULL	2	Using where; Using index
+DROP TABLE t1,t2;
+#
+# End of 10.0 tests
+#
diff --git a/mysql-test/r/type_varchar.result b/mysql-test/r/type_varchar.result
index 38ed8a47339..965d113124b 100644
--- a/mysql-test/r/type_varchar.result
+++ b/mysql-test/r/type_varchar.result
@@ -510,3 +510,44 @@ SELECT 5 = a FROM t1;
 Warnings:
 Warning	1292	Truncated incorrect DOUBLE value: 's               '
 DROP TABLE t1;
+#
+# Start of 10.0 tests
+#
+#
+# MDEV-6950 Bad results with joins comparing DATE and INT/ENUM/VARCHAR columns
+#
+CREATE TABLE t1 (c1 DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('2001-01-01');
+CREATE TABLE t2 (c1 VARCHAR(20));
+INSERT INTO t2 VALUES ('2001-01-01');
+INSERT INTO t2 VALUES ('2001/01/01');
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+ALTER TABLE t2 ADD PRIMARY KEY(c1);
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+EXPLAIN SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	PRIMARY	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	22	NULL	2	Using where; Using index
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+c1
+2001-01-01
+2001-01-01
+# t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	system	NULL	NULL	NULL	NULL	1	
+1	SIMPLE	t2	index	PRIMARY	PRIMARY	22	NULL	2	Using where; Using index
+DROP TABLE IF EXISTS t1,t2;
+#
+# End of 10.0 tests
+#
diff --git a/mysql-test/t/type_enum.test b/mysql-test/t/type_enum.test
index 5b0b70631a5..0a4bdc864e3 100644
--- a/mysql-test/t/type_enum.test
+++ b/mysql-test/t/type_enum.test
@@ -236,3 +236,30 @@ SELECT AVG(f1) FROM t1;
 drop table t1;
 
 --echo End of 5.3 tests
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-6950 Bad results with joins comparing DATE/DATETIME and INT/ENUM/VARCHAR columns
+--echo #
+
+CREATE TABLE t1 (c1 DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('2001-01-01');
+CREATE TABLE t2 (c1 ENUM('2001-01-01','2001/01/01'));
+INSERT INTO t2 VALUES ('2001-01-01');
+INSERT INTO t2 VALUES ('2001/01/01');
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+ALTER TABLE t2 ADD PRIMARY KEY(c1);
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+EXPLAIN SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+SELECT t1.* FROM t1 LEFT JOIN t2 USING (c1);
+--echo # t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 USING (c1);
+DROP TABLE t1, t2;
+
+--echo #
+--echo # End of 10.0 tests
+--echo #
diff --git a/mysql-test/t/type_float.test b/mysql-test/t/type_float.test
index 96ce1bcbd9e..bb7a784553e 100644
--- a/mysql-test/t/type_float.test
+++ b/mysql-test/t/type_float.test
@@ -343,3 +343,45 @@ INSERT INTO t1 VALUES ('2.0.');
 INSERT INTO t1 VALUES ('.');
 SELECT * FROM t1 ORDER BY f;
 DROP TABLE t1;
+
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-6950 Bad results with joins comparing DATE/DATETIME and INT/DECIMAL/DOUBLE/ENUM/VARCHAR columns
+--echo #
+CREATE TABLE t1 (a DATETIME PRIMARY KEY);
+INSERT INTO t1 VALUES ('1999-01-01 00:00:00');
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES (19990101000000);
+INSERT INTO t2 VALUES (990101000000);  
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+--echo # t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+DROP TABLE t1,t2; 
+
+--echo #
+--echo # MDEV-6971 Bad results with joins comparing TIME and DOUBLE/DECIMAL columns
+--echo #
+CREATE TABLE t1 (a TIME(6) PRIMARY KEY);
+INSERT INTO t1 VALUES ('10:20:30');
+CREATE TABLE t2 (a DOUBLE);
+INSERT INTO t2 VALUES (102030),(102030.000000001);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+--echo # t2 should NOT be elimitated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+DROP TABLE t1,t2;
+
+--echo #
+--echo # End of 10.0 tests
+--echo #
diff --git a/mysql-test/t/type_newdecimal.test b/mysql-test/t/type_newdecimal.test
index bb5a61d84ec..09149253c67 100644
--- a/mysql-test/t/type_newdecimal.test
+++ b/mysql-test/t/type_newdecimal.test
@@ -1581,3 +1581,44 @@ select 0.000000000000000000000000000000000000000000000000001 mod 1;
 select 0.0000000001 mod 1;
 select 0.01 mod 1;
 
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-6950 Bad results with joins comparing DATE and INT/ENUM/VARCHAR columns
+--echo #
+CREATE TABLE t1 (a DATETIME PRIMARY KEY);
+INSERT INTO t1 VALUES ('1999-01-01 00:00:00');
+CREATE TABLE t2 (a DECIMAL(30,1));
+INSERT INTO t2 VALUES (19990101000000);
+INSERT INTO t2 VALUES (990101000000);  
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+--echo # t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+DROP TABLE t1,t2; 
+
+--echo #
+--echo # MDEV-6971 Bad results with joins comparing TIME and DOUBLE/DECIMAL columns
+--echo #
+CREATE TABLE t1 (a TIME(6) PRIMARY KEY);
+INSERT INTO t1 VALUES ('10:20:30');
+CREATE TABLE t2 (a DECIMAL(30,10));
+INSERT INTO t2 VALUES (102030),(102030.000000001);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1 JOIN t2 USING(a);
+SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+--echo # t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 USING(a);
+DROP TABLE t1,t2;
+
+
+--echo #
+--echo # End of 10.0 tests
+--echo #
diff --git a/mysql-test/t/type_set.test b/mysql-test/t/type_set.test
index a851d116743..35729b277cd 100644
--- a/mysql-test/t/type_set.test
+++ b/mysql-test/t/type_set.test
@@ -95,3 +95,30 @@ DROP TABLE t1;
 
 
 --echo End of 5.0 tests
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-6950 Bad results with joins compating DATE and INT/ENUM/VARCHAR columns
+--echo #
+
+CREATE TABLE t1 (c1 DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('2001-01-01');
+CREATE TABLE t2 (c1 SET('2001-01-01','2001/01/01'));
+INSERT INTO t2 VALUES ('2001-01-01');
+INSERT INTO t2 VALUES ('2001/01/01');
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+ALTER TABLE t2 ADD PRIMARY KEY(c1);
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+EXPLAIN SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+--echo # t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+DROP TABLE t1, t2;
+
+--echo #
+--echo # End of 10.0 tests
+--echo #
diff --git a/mysql-test/t/type_uint.test b/mysql-test/t/type_uint.test
index a9212183cb6..3a949c5c47a 100644
--- a/mysql-test/t/type_uint.test
+++ b/mysql-test/t/type_uint.test
@@ -15,3 +15,29 @@ select * from t1;
 drop table t1;
 
 # End of 4.1 tests
+
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-6950 Bad results with joins comparing DATE and INT/ENUM/VARCHAR columns
+--echo #
+CREATE TABLE t1 (a DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('1999-01-01');
+CREATE TABLE t2 (a INT UNSIGNED);
+INSERT INTO t2 VALUES (19990101);
+INSERT INTO t2 VALUES (990101);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+ALTER TABLE t2 ADD PRIMARY KEY(a);
+SELECT t1.* FROM t1,t2 WHERE t1.a=t2.a;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+--echo # t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.a=t2.a;
+DROP TABLE t1,t2;
+
+--echo #
+--echo # End of 10.0 tests
+--echo #
diff --git a/mysql-test/t/type_varchar.test b/mysql-test/t/type_varchar.test
index 33b84266118..528d26d6f86 100644
--- a/mysql-test/t/type_varchar.test
+++ b/mysql-test/t/type_varchar.test
@@ -217,3 +217,29 @@ CREATE TABLE t1 (a CHAR(16));
 INSERT INTO t1 VALUES ('5'), ('s'), ('');
 SELECT 5 = a FROM t1;
 DROP TABLE t1;
+
+--echo #
+--echo # Start of 10.0 tests
+--echo #
+
+--echo #
+--echo # MDEV-6950 Bad results with joins comparing DATE and INT/ENUM/VARCHAR columns
+--echo #
+CREATE TABLE t1 (c1 DATE PRIMARY KEY);
+INSERT INTO t1 VALUES ('2001-01-01');
+CREATE TABLE t2 (c1 VARCHAR(20));
+INSERT INTO t2 VALUES ('2001-01-01');
+INSERT INTO t2 VALUES ('2001/01/01');
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+ALTER TABLE t2 ADD PRIMARY KEY(c1);
+SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+EXPLAIN SELECT t1.* FROM t1,t2 WHERE t1.c1=t2.c1;
+SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+--echo # t2 should NOT be eliminated
+EXPLAIN SELECT t1.* FROM t1 LEFT JOIN t2 ON t1.c1=t2.c1;
+DROP TABLE IF EXISTS t1,t2;
+
+--echo #
+--echo # End of 10.0 tests
+--echo #