In case of low memory sort buffer QUICK_INDEX_MERGE_SELECT creates
temporary file where is stores row ids which meet QUICK_SELECT ranges
except of clustered pk range, clustered range is processed separately.
In init_read_record we check if temporary file is used and choose
appropriate record access method. It does not take into account that
temporary file contains partial result in case of QUICK_INDEX_MERGE_SELECT
with clustered pk range.
The fix is always to use rr_quick if QUICK_INDEX_MERGE_SELECT
with clustered pk range is used.