BUG#26238 - inserted delayed always inserts 0 for BIT columns

INSERT DELAYED inserts garbage for BIT columns.

When delayed thread clones TABLE object, it didn't adjusted bit_ptr
to newly created record (though it correctly adjusts ptr and null_ptr).

This is fixed by correctly adjusting bit_ptr when performing a clone.
With this fix BIT values are stored correctly by INSERT DELAYED.

mysql-test/r/delayed.result

@@ -243,3 +243,10 @@ SET             @@session.auto_increment_offset=
 @bug20830_old_session_auto_increment_offset;
 SET             @@session.auto_increment_increment=
 @bug20830_old_session_auto_increment_increment;
+CREATE TABLE t1(a BIT);
+INSERT DELAYED INTO t1 VALUES(1);
+FLUSH TABLE t1;
+SELECT HEX(a) FROM t1;
+HEX(a)
+1
+DROP TABLE t1;

mysql-test/t/delayed.test

@@ -234,3 +234,11 @@ SET             @@session.auto_increment_offset=
 SET             @@session.auto_increment_increment=
     @bug20830_old_session_auto_increment_increment;
 
+#
+# BUG#26238 - inserted delayed always inserts 0 for BIT columns
+#
+CREATE TABLE t1(a BIT);
+INSERT DELAYED INTO t1 VALUES(1);
+FLUSH TABLE t1;
+SELECT HEX(a) FROM t1;
+DROP TABLE t1;

sql/field.h

@@ -225,7 +225,7 @@ class Field
     ptr=ptr_arg; null_ptr=null_ptr_arg; null_bit=null_bit_arg;
   }
   inline void move_field(char *ptr_arg) { ptr=ptr_arg; }
-  inline void move_field(my_ptrdiff_t ptr_diff)
+  virtual inline void move_field(my_ptrdiff_t ptr_diff)
   {
     ptr=ADD_TO_PTR(ptr,ptr_diff,char*);
     if (null_ptr)
@@ -1407,6 +1407,11 @@ class Field_bit :public Field {
   Field *new_key_field(MEM_ROOT *root, struct st_table *new_table,
                        char *new_ptr, uchar *new_null_ptr,
                        uint new_null_bit);
+  inline void move_field(my_ptrdiff_t ptr_diff)
+  {
+    Field::move_field(ptr_diff);
+    bit_ptr= ADD_TO_PTR(bit_ptr, ptr_diff, uchar*);
+  }
   void set_bit_ptr(uchar *bit_ptr_arg, uchar bit_ofs_arg)
   {
     bit_ptr= bit_ptr_arg;