Merge moonlight.intranet:/home/tomash/src/mysql_ab/mysql-4.1-bug17047

into  moonlight.intranet:/home/tomash/src/mysql_ab/mysql-5.0-bug17047

mysql-test/r/func_in.result

@@ -202,6 +202,14 @@ select count(*) from t1 where id not in (1,2);
 count(*)
 1
 drop table t1;
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 SELECT 1 IN (2, NULL);
+SELECT should return NULL.
+SELECT * FROM t1;
+1 IN (2, NULL)
+NULL
+DROP TABLE t1;
+End of 4.1 tests
 CREATE TABLE t1 (a int PRIMARY KEY);
 INSERT INTO t1 VALUES (44), (45), (46);
 SELECT * FROM t1 WHERE a IN (45);
@@ -343,3 +351,4 @@ some_id
 1
 2
 drop table t1;
+End of 5.0 tests

mysql-test/t/func_in.test

@@ -109,7 +109,28 @@ select count(*) from t1 where id not in (1);
 select count(*) from t1 where id not in (1,2);
 drop table t1;
 
-# End of 4.1 tests
+
+#
+# BUG#17047: CHAR() and IN() can return NULL without signaling NULL
+# result
+#
+# The problem was in the IN() function that ignored maybe_null flags
+# of all arguments except the first (the one _before_ the IN
+# keyword, '1' in the test case below).
+#
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1 SELECT 1 IN (2, NULL);
+--echo SELECT should return NULL.
+SELECT * FROM t1;
+
+DROP TABLE t1;
+
+
+--echo End of 4.1 tests
+
 
 #
 # Bug #11885: WHERE condition with NOT IN (one element)          
@@ -232,3 +253,6 @@ select some_id from t1 where some_id not in(2,-1);
 select some_id from t1 where some_id not in(-4,-1,-4);
 select some_id from t1 where some_id not in(-4,-1,3423534,2342342);
 drop table t1;
+
+
+--echo End of 5.0 tests

sql/item_cmpfunc.cc

@@ -2465,7 +2465,6 @@ void Item_func_in::fix_length_and_dec()
     if (cmp_type  == STRING_RESULT)
       in_item->cmp_charset= cmp_collation.collation;
   }
-  maybe_null= args[0]->maybe_null;
   max_length= 1;
 }