postgres-github.git / summary / log / commit / refs

commit    f6936bf9da58afd167787635863bae387ae5ba35
Author:   Richard Guo <rguo@postgresql.org>
Date:     Fri Apr 10 06:51:00 2026 +0000

    Fix var_is_nonnullable() to account for varreturningtype
    
    var_is_nonnullable() failed to consider varreturningtype, which meant
    it could incorrectly claim a Var is non-nullable based on a column's
    NOT NULL constraint even when the Var refers to a non-existent row.
    Specifically, OLD.col is NULL for INSERT (no old row exists) and
    NEW.col is NULL for DELETE (no new row exists), regardless of any NOT
    NULL constraint on the column.
    
    This caused the planner's constant folding in eval_const_expressions
    to incorrectly simplify IS NULL / IS NOT NULL tests on such Vars.  For
    example, "old.a IS NULL" in an INSERT's RETURNING clause would be
    folded to false when column "a" has a NOT NULL constraint, even though
    the correct result is true.
    
    Fix by returning false from var_is_nonnullable() when varreturningtype
    is not VAR_RETURNING_DEFAULT, since such Vars can be NULL regardless
    of table constraints.
    
    Author: SATYANARAYANA NARLAPURAM <satyanarlapuram@gmail.com>
    Reviewed-by: Tender Wang <tndrwang@gmail.com>
    Reviewed-by: Richard Guo <guofenglinux@gmail.com>
    Discussion: https://postgr.es/m/CAHg+QDfaAipL6YzOq2H=gAhKBbcUTYmfbAv+W1zueOfRKH43FQ@mail.gmail.com

[parent: 155c03ee9d44]