Adding EXPLAIN SELECT tests for:

MDEV-7649 wrong result when comparing utf8 column with an invalid literal
This is a preparatory patch for:
MDEV-8433 Make field<'broken-string' use indexes

mysql-test/include/ctype_utf8_ilseq.inc

@@ -28,17 +28,35 @@ INSERT INTO t1 (ch) VALUES (_utf8 0x61D680);
 
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
+--replace_column 9 #
+EXPLAIN
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+--replace_column 9 #
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
+--replace_column 9 #
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
+--replace_column 9 #
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
+--replace_column 9 #
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
+--replace_column 9 #
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 
 ALTER TABLE t1 DROP KEY ch;

mysql-test/r/ctype_uca.result

@@ -6506,10 +6506,22 @@ SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
 Warnings:
@@ -6552,6 +6564,12 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 ch
 a
@@ -6573,6 +6591,12 @@ aЀ
 aր
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 ch
 a
@@ -6600,11 +6624,23 @@ z
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 ch
 z
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
@@ -6714,10 +6750,22 @@ SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
 Warnings:
@@ -6760,6 +6808,10 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 ch
 a
@@ -6779,6 +6831,10 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 ch
 a
@@ -6804,9 +6860,17 @@ z
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z

mysql-test/r/ctype_uca_innodb.result

@@ -42,10 +42,22 @@ SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
 Warnings:
@@ -88,6 +100,12 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 ch
 a
@@ -109,6 +127,12 @@ aЀ
 aր
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 ch
 a
@@ -136,11 +160,23 @@ z
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 ch
 z
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z

mysql-test/r/ctype_utf8.result

@@ -5460,10 +5460,22 @@ SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
 Warnings:
@@ -5506,6 +5518,12 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 ch
 a
@@ -5527,6 +5545,12 @@ aЀ
 aր
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 ch
 a
@@ -5554,11 +5578,23 @@ z
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 ch
 z
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
@@ -5668,10 +5704,22 @@ SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
 Warnings:
@@ -5714,6 +5762,12 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 ch
 a
@@ -5735,6 +5789,12 @@ aЀ
 aր
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 ch
 a
@@ -5762,11 +5822,23 @@ z
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 ch
 z
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	index	ch	ch	182	NULL	#	Using where; Using index
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
@@ -5876,10 +5948,22 @@ SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆' ORDER BY ch;
 ch
 Warnings:
 Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86' for column 'ch' at row 1
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	#	Impossible WHERE noticed after reading const tables
+Warnings:
+Warning	1366	Incorrect string value: '\xF0\x9D\x8C\x86b' for column 'ch' at row 1
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch='a𝌆b' ORDER BY ch;
 ch
 Warnings:
@@ -5922,6 +6006,10 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆' ORDER BY ch;
 ch
 a
@@ -5941,6 +6029,10 @@ ab
 az
 aЀ
 aր
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch<'a𝌆b' ORDER BY ch;
 ch
 a
@@ -5966,9 +6058,17 @@ z
 SELECT ch FROM t1 IGNORE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆' ORDER BY ch;
 ch
 z
+EXPLAIN
+SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	ALL	ch	NULL	NULL	NULL	#	Using where; Using filesort
 SELECT ch FROM t1 FORCE KEY (ch) WHERE ch>'a𝌆b' ORDER BY ch;
 ch
 z