This bug was introduced in
commit 7ae21b18a6b73bbc3bf1ff448faf60c29ac1d386
(the main commit of MDEV-12353).
page_cur_insert_rec_low(): Before entering the comparison loop, make sure
that the range does not exceed c_end already at the start of the loop.
The loop is only comparing for pointer equality, and that condition
cdm == c_end would never hold if the end was already exceeded in
the beginning. Also, skip the comparison altogether if we could find
at most 2 equal bytes.
PageBulk::insertPage(): Apply a similar change. It seems that this
code was correct, because the loop checks for cdm < c_end.
mtr_t::page_delete(): Write DELETE_ROW_FORMAT_REDUNDANT or
DELETE_ROW_FORMAT_DYNAMIC log records. We log the byte offset
of the preceding record, so that on recovery we can easily
find everything to update. For DELETE_ROW_FORMAT_DYNAMIC,
we must also write the header and data size of the record.
We will retain the physical logging for ROW_FORMAT=COMPRESSED pages.
page_zip_dir_balance_slot(): Renamed from page_dir_balance_slot(),
and specialized for ROW_FORMAT=COMPRESSED only.
page_rec_set_n_owned(), page_dir_slot_set_n_owned(),
page_dir_balance_slot(): New variants that do not write any log.
page_mem_free(): Take data_size, extra_size as parameters.
Always zerofill the record payload.
page_cur_delete_rec(): For other than ROW_FORMAT=COMPRESSED,
only write log by mtr_t::page_delete().
