database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00
Code Activity

BUG#26969:

Browse Source 
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
This commit is contained in:
mats@romeo.(none)
2007-03-20 14:13:07 +01:00
parent 6a01170299
commit b1f69b48ef
2 changed files with 31 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
sql/field.cc
View File

@ -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);