diff --git a/mysql-test/r/func_in.result b/mysql-test/r/func_in.result
index 88a822a2fa6..ffdacc43735 100644
--- a/mysql-test/r/func_in.result
+++ b/mysql-test/r/func_in.result
@@ -608,4 +608,146 @@ SELECT SUM( DISTINCT e ) FROM t1 GROUP BY b,c,d HAVING (b,c,d) IN
 ((AVG( 1 ), 1 + c, 1 + d), (AVG( 1 ), 2 + c, 2 + d));
 SUM( DISTINCT e )
 DROP TABLE t1;
+#
+# Bug #44139: Table scan when NULL appears in IN clause
+#
+CREATE TABLE t1 (
+c_int INT NOT NULL,
+c_decimal DECIMAL(5,2) NOT NULL,
+c_float FLOAT(5, 2) NOT NULL,
+c_bit BIT(10) NOT NULL,
+c_date DATE NOT NULL, 
+c_datetime DATETIME NOT NULL,
+c_timestamp TIMESTAMP NOT NULL,
+c_time TIME NOT NULL,
+c_year YEAR NOT NULL,
+c_char CHAR(10) NOT NULL,
+INDEX(c_int), INDEX(c_decimal), INDEX(c_float), INDEX(c_bit), INDEX(c_date),
+INDEX(c_datetime), INDEX(c_timestamp), INDEX(c_time), INDEX(c_year),
+INDEX(c_char));
+INSERT INTO t1 (c_int) VALUES (1), (2), (3), (4), (5);
+INSERT INTO t1 (c_int) SELECT 0 FROM t1;
+INSERT INTO t1 (c_int) SELECT 0 FROM t1;
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL, 1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, NULL, 2, NULL, 3, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_int	c_int	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_decimal	c_decimal	3	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL, 1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_decimal	c_decimal	3	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_float	c_float	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL, 1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_float	c_float	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_bit	c_bit	2	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL, 1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_bit	c_bit	2	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_date 
+IN ('2009-09-01', '2009-09-02', '2009-09-03');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_date	c_date	3	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_date
+IN (NULL, '2009-09-01', '2009-09-02', '2009-09-03');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_date	c_date	3	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_datetime
+IN ('2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_datetime	c_datetime	8	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_datetime
+IN (NULL, '2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_datetime	c_datetime	8	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp
+IN ('2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_timestamp	c_timestamp	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp
+IN (NULL, '2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_timestamp	c_timestamp	4	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_year	c_year	1	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL, 1, 2, 3);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_year	c_year	1	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_char IN ('1', '2', '3');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_char	c_char	10	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL, '1', '2', '3');
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	t1	range	c_char	c_char	10	NULL	3	Using where
+EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL, NULL);
+id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
+1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	Impossible WHERE noticed after reading const tables
+DROP TABLE t1;
+#
 End of 5.1 tests
diff --git a/mysql-test/t/func_in.test b/mysql-test/t/func_in.test
index adc074259ad..61ae812d874 100644
--- a/mysql-test/t/func_in.test
+++ b/mysql-test/t/func_in.test
@@ -456,4 +456,89 @@ SELECT SUM( DISTINCT e ) FROM t1 GROUP BY b,c,d HAVING (b,c,d) IN
   ((AVG( 1 ), 1 + c, 1 + d), (AVG( 1 ), 2 + c, 2 + d));
 DROP TABLE t1;
 
+--echo #
+--echo # Bug #44139: Table scan when NULL appears in IN clause
+--echo #
+
+--disable_warnings
+
+CREATE TABLE t1 (
+  c_int INT NOT NULL,
+  c_decimal DECIMAL(5,2) NOT NULL,
+  c_float FLOAT(5, 2) NOT NULL,
+  c_bit BIT(10) NOT NULL,
+  c_date DATE NOT NULL, 
+  c_datetime DATETIME NOT NULL,
+  c_timestamp TIMESTAMP NOT NULL,
+  c_time TIME NOT NULL,
+  c_year YEAR NOT NULL,
+  c_char CHAR(10) NOT NULL,
+  INDEX(c_int), INDEX(c_decimal), INDEX(c_float), INDEX(c_bit), INDEX(c_date),
+  INDEX(c_datetime), INDEX(c_timestamp), INDEX(c_time), INDEX(c_year),
+  INDEX(c_char));
+
+INSERT INTO t1 (c_int) VALUES (1), (2), (3), (4), (5);
+INSERT INTO t1 (c_int) SELECT 0 FROM t1;
+INSERT INTO t1 (c_int) SELECT 0 FROM t1;
+
+--enable_warnings
+
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL, 1, 2, 3);
+
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (1, NULL, 2, NULL, 3, NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_int IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL, 1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_decimal IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL, 1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_float IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL, 1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_bit IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_date 
+  IN ('2009-09-01', '2009-09-02', '2009-09-03');
+EXPLAIN SELECT * FROM t1 WHERE c_date
+  IN (NULL, '2009-09-01', '2009-09-02', '2009-09-03');
+EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_date IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_datetime
+  IN ('2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01');
+EXPLAIN SELECT * FROM t1 WHERE c_datetime
+  IN (NULL, '2009-09-01 00:00:01', '2009-09-02 00:00:01', '2009-09-03 00:00:01');
+EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_datetime IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp
+  IN ('2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03');
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp
+  IN (NULL, '2009-09-01 00:00:01', '2009-09-01 00:00:02', '2009-09-01 00:00:03');
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_timestamp IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL, 1, 2, 3);
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_year IN (NULL, NULL);
+
+EXPLAIN SELECT * FROM t1 WHERE c_char IN ('1', '2', '3');
+EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL, '1', '2', '3');
+EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL);
+EXPLAIN SELECT * FROM t1 WHERE c_char IN (NULL, NULL);
+
+DROP TABLE t1;
+
+--echo #
+
 --echo End of 5.1 tests
diff --git a/sql/item_cmpfunc.cc b/sql/item_cmpfunc.cc
index d229453b795..c29031d25b5 100644
--- a/sql/item_cmpfunc.cc
+++ b/sql/item_cmpfunc.cc
@@ -189,6 +189,7 @@ enum_field_types agg_field_type(Item **items, uint nitems)
     collect_cmp_types()
       items             Array of items to collect types from
       nitems            Number of items in the array
+      skip_nulls        Don't collect types of NULL items if TRUE
 
   DESCRIPTION
     This function collects different result types for comparison of the first
@@ -199,7 +200,7 @@ enum_field_types agg_field_type(Item **items, uint nitems)
     Bitmap of collected types - otherwise
 */
 
-static uint collect_cmp_types(Item **items, uint nitems)
+static uint collect_cmp_types(Item **items, uint nitems, bool skip_nulls= FALSE)
 {
   uint i;
   uint found_types;
@@ -208,6 +209,8 @@ static uint collect_cmp_types(Item **items, uint nitems)
   found_types= 0;
   for (i= 1; i < nitems ; i++)
   {
+    if (skip_nulls && items[i]->type() == Item::NULL_ITEM)
+      continue; // Skip NULL constant items
     if ((left_result == ROW_RESULT || 
          items[i]->result_type() == ROW_RESULT) &&
         cmp_row_type(items[0], items[i]))
@@ -215,6 +218,12 @@ static uint collect_cmp_types(Item **items, uint nitems)
     found_types|= 1<< (uint)item_cmp_type(left_result,
                                            items[i]->result_type());
   }
+  /*
+   Even if all right-hand items are NULLs and we are skipping them all, we need
+   at least one type bit in the found_type bitmask.
+  */
+  if (skip_nulls && !found_types)
+    found_types= 1 << (uint)left_result;
   return found_types;
 }
 
@@ -3515,7 +3524,7 @@ void Item_func_in::fix_length_and_dec()
   uint type_cnt= 0, i;
   Item_result cmp_type= STRING_RESULT;
   left_result_type= args[0]->result_type();
-  if (!(found_types= collect_cmp_types(args, arg_count)))
+  if (!(found_types= collect_cmp_types(args, arg_count, true)))
     return;
   
   for (arg= args + 1, arg_end= args + arg_count; arg != arg_end ; arg++)
@@ -3693,9 +3702,11 @@ void Item_func_in::fix_length_and_dec()
       uint j=0;
       for (uint i=1 ; i < arg_count ; i++)
       {
-	array->set(j,args[i]);
 	if (!args[i]->null_value)			// Skip NULL values
+        {
+          array->set(j,args[i]);
 	  j++;
+        }
 	else
 	  have_null= 1;
       }