In deparsing, parenthesize IS DOCUMENT where it is an operand. isSimpleNode() and related code treated every XmlExpr as self-delimiting. Most of them are, because they look like function calls with some extra decoration. But "x IS DOCUMENT" is not: it is a postfix test, like IS NULL. Printed as the operand of another operator, or as the operand of a postfix test, it was therefore not parenthesized and could not be parsed back, or was parsed as something unintended. Under-parenthesization occurred even in non-pretty-print cases, so that this could break dump/restore workflows.
To fix, treat IS DOCUMENT as neither simple nor function-like, and give it the same treatment as other postfix tests. Also pass the single argument of IS DOCUMENT, not the argument list, to get_rule_expr_paren(). This avoids unnecessary parenthesization of the argument. Author: Henson Choi <[email protected]> Reviewed-by: Prashant Chinnam <[email protected]> Reviewed-by: Tom Lane <[email protected]> Discussion: https://postgr.es/m/caaae_zdupskc8ihcctv67lxbqock+s4wqchho8xxz1t4tex...@mail.gmail.com Backpatch-through: 14 Branch ------ REL_18_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/b08c4df3b733a77ae6404bee51ce0daa9d8a59cc Modified Files -------------- src/backend/utils/adt/ruleutils.c | 33 ++++++++++++++++++++++++++----- src/test/regress/expected/create_view.out | 21 +++++++++++++++++++- src/test/regress/sql/create_view.sql | 10 ++++++++++ 3 files changed, 58 insertions(+), 6 deletions(-)
