Commit bd299fdf authored by unknown's avatar unknown
Browse files

BUG#26969: 

  Field_bit::pack() and Field_bit::unpack() does not work correctly

Fixing code for Field_bit packing and unpacking to work with arbitrary
pointers instead of requiring Field::ptr


sql/field.cc:
  Fixing Field_bit::pack() and Field_bit::unpack() so that they accept
  an arbitrary pointer to pack/unpack to/from.
sql/sql_class.cc:
  Removing unneeded move_field_offset() nefore packing field.
parent 44c41cc2

sql/field.cc

+30 −4
Original line number Diff line number Diff line
@@ -8505,9 +8505,28 @@ char *Field_bit::pack(char *to, const char *from, uint max_length) 
{

  DBUG_ASSERT(max_length);

  uint length;

  if (bit_len)

  if (bit_len > 0)

  {

    uchar bits= get_rec_bits(bit_ptr, bit_ofs, bit_len);

    /*

      We have the following:



      ptr        Points into a field in record R1

      from       Points to a field in a record R2

      bit_ptr    Points to the byte (in the null bytes) that holds the

                 odd bits of R1

      from_bitp  Points to the byte that holds the odd bits of R2



      We have the following:



          ptr - bit_ptr = from - from_bitp



      We want to isolate 'from_bitp', so this gives:



          ptr - bit_ptr - from = - from_bitp

          - ptr + bit_ptr + from = from_bitp

          bit_ptr + from - ptr = from_bitp

     */

    uchar bits= get_rec_bits(bit_ptr + (from - ptr), bit_ofs, bit_len);

    *to++= bits;

  }

  length= min(bytes_in_rec, max_length - (bit_len > 0));
@@ -8518,9 +8537,16 @@ char *Field_bit::pack(char *to, const char *from, uint max_length) 


const char *Field_bit::unpack(char *to, const char *from)

{

  if (bit_len)

  if (bit_len > 0)

  {

    set_rec_bits(*from, bit_ptr, bit_ofs, bit_len);

    /*

      set_rec_bits is a macro, don't put the post-increment in the

      argument since that might cause strange side-effects.



      For the choice of the second argument, see the explanation for

      Field_bit::pack().

    */

    set_rec_bits(*from, bit_ptr + (to - ptr), bit_ofs, bit_len);

    from++;

  }

  memcpy(to, from, bytes_in_rec);

sql/sql_class.cc

+1 −3
Original line number Diff line number Diff line
@@ -2619,9 +2619,7 @@ THD::pack_row(TABLE *table, MY_BITMAP const* cols, 
        /*

          We only store the data of the field if it is non-null

         */

        field->move_field_offset(offset);

        pack_ptr= (byte*)field->pack((char *) pack_ptr, field->ptr);

        field->move_field_offset(-offset);

        pack_ptr= (byte*)field->pack((char *) pack_ptr, field->ptr + offset);

      }



      null_mask <<= 1;