d260d7d003
The code added in c456e3911 added populate_isnull_array() to bulk
populate the slot's tts_isnull array 8 elements at a time. When tuples
don't have an exact multiple-of-eight number of attributes, this will
lead to populating the tts_isnull elements for attributes that don't
exist in the tuple. This is ok as the array is large enough. However,
if we perform tuple deforming in two passes, and on the first pass
deform *some* of the attributes with slot_getmissingattrs() then later
when we deform the remaining missing attributes, the subsequent call to
populate_isnull_array() would overwrite the tts_isnull values previously
set by slot_getmissingattrs(), and since that function only continues
where it left off, it wouldn't reapply the previously set values and those
would be left as NULLs, as populate_isnull_array() would have set them.
Here, we fix by passing the tuple's natts to slot_getmissingattrs()
rather than the attnum we're deforming from. This means we apply all
the missing attribute values each deform pass, so slightly more work,
but deforming several missing values in different deform passes is
likely exceedingly rare. Doing that seems much better than adding
overhead in the happy path to check for this and skip the subsequent call
to populate_isnull_array().
Author: David Rowley <dgrowleyml@gmail.com>
Reported-by: Peter Geoghegan <pg@bowt.ie>
Discussion: https://postgr.es/m/CAH2-WznHo4b+6AmAj0GZ0jXqDSK69MfHe8fAQwuY_01y7cVNdw@mail.gmail.com
Backpatch-through: 19
PostgreSQL Database Management System
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