Bug #21618: NULL shown as empty string in client

The column's NOT NULL flag doesn't affect what we should print.  Remove the
wrong logic that does check it.

Also, verify that this and the previous two tests print the same data as 
other output formats.


client/mysql.cc:
  Don't check the column's NOT NULL flag when determining whether to print 
  "NULL" or not.
mysql-test/r/mysql.result:
  Add results and confirm that the other output forms give the same results
  for other similar tests.
mysql-test/t/mysql.test:
  Add regression tests for this bug and two similar bugs.

client/mysql.cc

@@ -2270,10 +2270,8 @@ print_table_data(MYSQL_RES *result)
   MYSQL_ROW	cur;
   MYSQL_FIELD	*field;
   bool		*num_flag;
-  bool		*not_null_flag;
 
   num_flag=(bool*) my_alloca(sizeof(bool)*mysql_num_fields(result));
-  not_null_flag=(bool*) my_alloca(sizeof(bool)*mysql_num_fields(result));
   if (info_flag)
   {
     print_field_types(result);
@@ -2307,7 +2305,6 @@ print_table_data(MYSQL_RES *result)
                                             MAX_COLUMN_LENGTH),
 		  field->name);
       num_flag[off]= IS_NUM(field->type);
-      not_null_flag[off]= IS_NOT_NULL(field->flags);
     }
     (void) tee_fputs("\n", PAGER);
     tee_puts((char*) separator.ptr(), PAGER);
@@ -2328,7 +2325,7 @@ print_table_data(MYSQL_RES *result)
       uint extra_padding;
 
       /* If this column may have a null value, use "NULL" for empty.  */
-      if (! not_null_flag[off] && (cur[off] == NULL))
+      if (cur[off] == NULL)
       {
         buffer= "NULL";
         data_length= 4;
@@ -2368,7 +2365,6 @@ print_table_data(MYSQL_RES *result)
   }
   tee_puts((char*) separator.ptr(), PAGER);
   my_afree((gptr) num_flag);
-  my_afree((gptr) not_null_flag);
 }
 
 

mysql-test/r/mysql.result

@@ -85,6 +85,12 @@ c_cp932
 | NULL | NULL | Τη γλώσσα                 | 
 | NULL | NULL | ᛖᚴ ᚷᛖᛏ                    | 
 +------+------+---------------------------+
+i	j	k
+NULL	1	NULL
+Field	Type	Null	Key	Default	Extra
+i	int(11)	YES		NULL	
+j	int(11)	NO			
+k	int(11)	YES		NULL	
 +------+---+------+
 | i    | j | k    |
 +------+---+------+
@@ -97,6 +103,10 @@ c_cp932
 | j     | int(11) | NO   |     |         |       | 
 | k     | int(11) | YES  |     | NULL    |       | 
 +-------+---------+------+-----+---------+-------+
+i	s1
+1	x
+2	NULL
+3	
 +------+------+
 | i    | s1   |
 +------+------+
@@ -104,4 +114,11 @@ c_cp932
 |    2 | NULL | 
 |    3 |      | 
 +------+------+
+unhex('zz')
+NULL
++-------------+
+| unhex('zz') |
++-------------+
+| NULL        | 
++-------------+
 End of 5.0 tests

mysql-test/t/mysql.test

@@ -70,13 +70,21 @@ drop table t1;
 #
 # "DESCRIBE" commands may return strange NULLness flags.
 #
+--exec $MYSQL --default-character-set utf8 test -e "create table t1 (i int, j int not null, k int); insert into t1 values (null, 1, null); select * from t1; describe t1; drop table t1;"
 --exec $MYSQL -t --default-character-set utf8 test -e "create table t1 (i int, j int not null, k int); insert into t1 values (null, 1, null); select * from t1; describe t1; drop table t1;"
 
 #
 # Bug#19564: mysql displays NULL instead of space
 #
+--exec $MYSQL test -e "create table b19564 (i int, s1 char(1)); insert into b19564 values (1, 'x'); insert into b19564 values (2, NULL); insert into b19564 values (3, ' '); select * from b19564 order by i; drop table b19564;" 
 --exec $MYSQL -t test -e "create table b19564 (i int, s1 char(1)); insert into b19564 values (1, 'x'); insert into b19564 values (2, NULL); insert into b19564 values (3, ' '); select * from b19564 order by i; drop table b19564;" 
 
+#
+# Bug#21618: NULL shown as empty string in client
+#
+--exec $MYSQL test -e "select unhex('zz');" 
+--exec $MYSQL -t test -e "select unhex('zz');" 
+
 --echo End of 5.0 tests