More test coverage

mysql-test/main/statistics_json.result

@@ -8146,3 +8146,25 @@ analyze select * from t1 where a >= 0;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
 1	SIMPLE	t1	ALL	NULL	NULL	NULL	NULL	100	100.00	100.00	100.00	Using where
 drop table t1;
+#
+# More test coverage
+#
+create table t0(a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+create table t1(a int);
+insert into t1 select A.a + B.a* 10 + C.a * 100 from t0 A, t0 B, t0 C;
+create table t2 (a int);
+insert into t2 select 1 from t1;
+insert into t2 select (a+1)*10 from t0;
+insert into t2 values (0);
+analyze table t2 persistent for all;
+Table	Op	Msg_type	Msg_text
+test.t2	analyze	status	Engine-independent statistics collected
+test.t2	analyze	status	OK
+analyze select * from t2 where a < 1;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1011	1011.00	8.33	0.10	Using where
+analyze select * from t2 where a =100;
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	r_rows	filtered	r_filtered	Extra
+1	SIMPLE	t2	ALL	NULL	NULL	NULL	NULL	1011	1011.00	0.10	0.10	Using where
+drop table t0,t1,t2;

mysql-test/main/statistics_json.test

@@ -353,3 +353,25 @@ analyze select * from t1 where a < 0;
 analyze select * from t1 where a > 0;
 analyze select * from t1 where a >= 0;
 drop table t1;
+
+
+--echo #
+--echo # More test coverage
+--echo #
+create table t0(a int);
+insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9);
+
+create table t1(a int);
+insert into t1 select A.a + B.a* 10 + C.a * 100 from t0 A, t0 B, t0 C;
+
+create table t2 (a int);
+insert into t2 select 1 from t1;
+insert into t2 select (a+1)*10 from t0;
+insert into t2 values (0);
+
+analyze table t2 persistent for all;
+analyze select * from t2 where a < 1;
+analyze select * from t2 where a =100;
+
+drop table t0,t1,t2;
+

sql/opt_histogram_json.cc

@@ -914,7 +914,6 @@ double Histogram_json_hb::range_selectivity(Field *field, key_range *min_endp,
       /*
         The range is "col > $CONST" and we've found a bucket that contains
         only the value $CONST. Move to the next bucket.
-        TODO: what if the last value in the histogram is a popular one?
       */
       idx++;
     }
@@ -948,7 +947,6 @@ double Histogram_json_hb::range_selectivity(Field *field, key_range *min_endp,
       /*
         The range is "col < $CONST" and we've found a bucket starting with
         $CONST. Move to the previous bucket.
-        TODO: what if the first value is the popular one?
       */
       idx--;
     }