pgsql/ oc/src/sgml/func.sgml oc/src/sgml/synta ...

CVSROOT:    /home/projects/pgsql/cvsroot
Module name:    pgsql
Changes by:    tgl@hub.org    01/06/19 18:39:12

Modified files:
    doc/src/sgml   : func.sgml syntax.sgml
    src/backend/executor: execQual.c
    src/backend/nodes: copyfuncs.c equalfuncs.c outfuncs.c
                       readfuncs.c
    src/backend/optimizer/util: clauses.c
    src/backend/parser: gram.y keywords.c parse_clause.c
                        parse_coerce.c parse_expr.c
    src/backend/utils/adt: ruleutils.c
    src/include/catalog: catversion.h
    src/include/nodes: nodes.h parsenodes.h
    src/include/parser: parse_coerce.h

Log message:
    Add IS UNKNOWN, IS NOT UNKNOWN boolean tests, fix the existing boolean
    tests to return the correct results per SQL9x when given NULL inputs.
    Reimplement these tests as well as IS [NOT] NULL to have their own
    expression node types, instead of depending on special functions.
    From Joe Conway, with a little help from Tom Lane.