MDEV-21683 Server crashes in get_quick_keys with not_null_range_scan

ANding of the range built from inferred NOT NULL conditions and the range
built from other conditions used in WHERE/ON clauses may produce an
IMPOSSIBLE range. The code of MDEV-15777 did not take into account this
possibility.

mysql-test/main/range.result

@@ -3116,7 +3116,6 @@ drop table t1,ten,t2;
 #
 # MDEV-15777: Use inferred IS NOT NULL predicates in the range optimizer
 #
-set @save_optimizer_switch= @@optimizer_switch;
 set @@optimizer_switch='not_null_range_scan=on';
 create table ten(a int);
 insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -3404,6 +3403,25 @@ drop table t1,t2;
 drop table ten,one_k;
 set @@optimizer_switch= @save_optimizer_switch;
 #
+# MDEV-21683: ANDing of the range from inferred NOT NULL condition and
+#             the range from other conditions produces IMPOSSIBLE range
+#
+SET @save_optimizer_switch= @@optimizer_switch;
+CREATE TABLE t1 (a INT, KEY(a));
+INSERT INTO t1 VALUES (8),(9);
+CREATE TABLE t2 (pk INT, b INT, PRIMARY KEY(pk));
+INSERT INTO t2 VALUES (1,1),(2,2);
+SET optimizer_switch = 'not_null_range_scan=on';
+EXPLAIN EXTENDED SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+Warnings:
+Note	1003	select NULL AS `a`,0 AS `pk`,NULL AS `b` from `test`.`t1` join `test`.`t2` where 0
+SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL;
+a	pk	b
+DROP TABLE t1, t2;
+SET @@optimizer_switch= @save_optimizer_switch;
+#
 # End of 10.5 tests
 #
 set global innodb_stats_persistent= @innodb_stats_persistent_save;

mysql-test/main/range.test

@@ -2106,7 +2106,6 @@ drop table t1,ten,t2;
 --echo # MDEV-15777: Use inferred IS NOT NULL predicates in the range optimizer
 --echo #
 
-set @save_optimizer_switch= @@optimizer_switch;
 set @@optimizer_switch='not_null_range_scan=on';
 create table ten(a int);
 insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -2280,6 +2279,29 @@ drop table t1,t2;
 drop table ten,one_k;
 set @@optimizer_switch= @save_optimizer_switch;
 
+--echo #
+--echo # MDEV-21683: ANDing of the range from inferred NOT NULL condition and
+--echo #             the range from other conditions produces IMPOSSIBLE range
+--echo #
+
+SET @save_optimizer_switch= @@optimizer_switch;
+
+CREATE TABLE t1 (a INT, KEY(a));
+INSERT INTO t1 VALUES (8),(9);
+
+CREATE TABLE t2 (pk INT, b INT, PRIMARY KEY(pk));
+INSERT INTO t2 VALUES (1,1),(2,2);
+
+SET optimizer_switch = 'not_null_range_scan=on';
+let $q=
+SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL;
+eval EXPLAIN EXTENDED $q;
+eval $q;
+
+DROP TABLE t1, t2;
+
+SET @@optimizer_switch= @save_optimizer_switch;
+
 --echo #
 --echo # End of 10.5 tests
 --echo #

mysql-test/main/range_mrr_icp.result

@@ -3113,7 +3113,6 @@ drop table t1,ten,t2;
 #
 # MDEV-15777: Use inferred IS NOT NULL predicates in the range optimizer
 #
-set @save_optimizer_switch= @@optimizer_switch;
 set @@optimizer_switch='not_null_range_scan=on';
 create table ten(a int);
 insert into ten values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
@@ -3401,6 +3400,25 @@ drop table t1,t2;
 drop table ten,one_k;
 set @@optimizer_switch= @save_optimizer_switch;
 #
+# MDEV-21683: ANDing of the range from inferred NOT NULL condition and
+#             the range from other conditions produces IMPOSSIBLE range
+#
+SET @save_optimizer_switch= @@optimizer_switch;
+CREATE TABLE t1 (a INT, KEY(a));
+INSERT INTO t1 VALUES (8),(9);
+CREATE TABLE t2 (pk INT, b INT, PRIMARY KEY(pk));
+INSERT INTO t2 VALUES (1,1),(2,2);
+SET optimizer_switch = 'not_null_range_scan=on';
+EXPLAIN EXTENDED SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+Warnings:
+Note	1003	select NULL AS `a`,0 AS `pk`,NULL AS `b` from `test`.`t1` join `test`.`t2` where 0
+SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL;
+a	pk	b
+DROP TABLE t1, t2;
+SET @@optimizer_switch= @save_optimizer_switch;
+#
 # End of 10.5 tests
 #
 set global innodb_stats_persistent= @innodb_stats_persistent_save;

sql/opt_range.cc

@@ -2838,12 +2838,15 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
     if (notnull_cond)
       notnull_cond_tree= notnull_cond->get_mm_tree(&param, &notnull_cond);
 
-    if (cond)
+    if (cond || notnull_cond_tree)
     {
       {
         Json_writer_array trace_range_summary(thd,
                                            "setup_range_conditions");
-        tree= cond->get_mm_tree(&param, &cond);
+        if (cond)
+          tree= cond->get_mm_tree(&param, &cond);
+        if (notnull_cond_tree)
+          tree= tree_and(&param, tree, notnull_cond_tree);
       }
       if (tree)
       {
@@ -2865,7 +2868,6 @@ int SQL_SELECT::test_quick_select(THD *thd, key_map keys_to_use,
         }
       }
     }
-    tree= tree_and(&param, tree, notnull_cond_tree);
 
     /*
       Try to construct a QUICK_GROUP_MIN_MAX_SELECT.