The following script:

<verbatim>
  create table t(x, y, unique(x, y));
  insert into t values(null, 1);
  insert into t values(null, 1);
  select * from t where x is null and y = 1;
</verbatim>

is returning one row instead of two.

Introduced here: [90e36676476e8db0]

First appeared in version 3.8.5

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